Pyrrole inhibitors of ERK protein kinase, synthesis thereof and intermediates thereto

ABSTRACT

The present invention relates to compounds useful of inhibitors of protein kinases. The invention also provides pharmaceutically acceptable compositions comprising said compounds and methods of using the compositions in the treatment of various disease, conditions, or disorders.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application60/571,309 filed May 14, 2004, the entire contents of which are herebyincorporated herein by reference.

TECHNICAL FIELD OF INVENTION

The present invention relates to compounds useful as inhibitors ofprotein kinases. The invention also provides pharmaceutically acceptablecompositions comprising the compounds of the invention and methods ofusing the compositions in the treatment of various disorders.

BACKGROUND OF THE INVENTION

The search for new therapeutic agents has been greatly aided in recentyears by a better understanding of the structure of enzymes and otherbiomolecules associated with target diseases. One important class ofenzymes that has been the subject of extensive study is protein kinases.

Protein kinases constitute a large family of structurally relatedenzymes that are responsible for the control of a variety of signaltransduction processes within the cell. (See, Hardie, G. and Hanks, S.(1995) The Protein Kinase Facts Book, I and II, Academic Press, SanDiego, Calif.). Protein kinases are thought to have evolved from acommon ancestral gene due to the conservation of their structure andcatalytic function. Almost all kinases contain a similar 250-300 aminoacid catalytic domain. The kinases may be categorized into families bythe substrates they phosphorylate (e.g., protein-tyrosine,protein-serine/threonine, lipids, etc.). Sequence motifs have beenidentified that generally correspond to each of these kinase families(See, for example, Hanks, S. K., Hunter, T., FASEB J., 9:576-596 (1995);Knighton et al., Science, 253:407-414 (1991); Hiles et al., Cell,70:419-429 (1992); Kunz et al., Cell, 73:585-596 (1993); Garcia-Bustoset al., EMBO J., 13:2352-2361 (1994)).

In general, protein kinases mediate intracellular signaling by effectinga phosphoryl transfer from a nucleoside triphosphate to a proteinacceptor that is involved in a signaling pathway. These phosphorylationevents act as molecular on/off switches that can modulate or regulatethe target protein biological function. These phosphorylation events areultimately triggered in response to a variety of extracellular and otherstimuli. Examples of such stimuli include environmental and chemicalstress signals (e.g., osmotic shock, heat shock, ultraviolet radiation,bacterial endotoxin, and H₂O₂), cytokines (e.g., interleukin-1 (IL-1)and tumor necrosis factor a (TNF-a)), and growth factors (e.g.,granulocyte macrophage-colony-stimulating factor (GM-CSF), andfibroblast growth factor (FGF)). An extracellular stimulus may affectone or more cellular responses related to cell growth, migration,differentiation, secretion of hormones, activation of transcriptionfactors, muscle contraction, glucose metabolism, control of proteinsynthesis, and regulation of the cell cycle.

Many diseases are associated with abnormal cellular responses triggeredby protein kinase-mediated events. These diseases include autoimmunediseases, inflammatory diseases, bone diseases, metabolic diseases,neurological and neurodegenerative diseases, cancer, cardiovasculardiseases, allergies and asthma, Alzheimer's disease and hormone-relateddiseases. Accordingly, there has been a substantial effort in medicinalchemistry to find protein kinase inhibitors that are effective astherapeutic agents. However, considering the lack of currently availabletreatment options for the majority of the conditions associated withprotein kinases, there is still a great need for new therapeutic agentsthat inhibit these protein targets.

Mammalian cells respond to extracellular stimuli by activating signalingcascades that are mediated by members of the mitogen-activated protein(MAP) kinase family, which include the extracellular signal regulatedkinases (ERKs), the p38 MAP kinases and the c-Jun N-terminal kinases(JNKs). MAP kinases (MAPKs) are activated by a variety of signalsincluding growth factors, cytokines, UV radiation, and stress-inducingagents. MAPKs are serine/threonine kinases and their activation occur bydual phosphorylation of threonine and tyrosine at the Thr-X-Tyr segmentin the activation loop. MAPKs phosphorylate various substrates includingtranscription factors, which in turn regulate the expression of specificsets of genes and thus mediate a specific response to the stimulus.

ERK2 is a widely distributed protein kinase that achieves maximumactivity when both Thr183 and Tyr185 are phosphorylated by the upstreamMAP kinase kinase, MEK1 (Anderson et al., 1990, Nature 343, 651; Crewset al., 1992, Science 258, 478). Upon activation, ERK2 phosphorylatesmany regulatory proteins, including the protein kinases Rsk90 (Bjorbaeket al., 1995, J. Biol. Chem. 270, 18848) and MAPKAP2 (Rouse et al.,1994, Cell 78, 1027), and transcription factors such as ATF2 (Raingeaudet al., 1996, Mol. Cell Biol. 16, 1247), Elk-1 (Raingeaud et al. 1996),c-Fos (Chen et al., 1993 Proc. Natl. Acad. Sci. USA 90, 10952), andc-Myc (Oliver et al., 1995, Proc. Soc. Exp. Biol. Med. 210, 162). ERK2is also a downstream target of the Ras/Raf dependent pathways (Moodie etal., 1993, Science 260, 1658) and relays the signals from thesepotentially oncogenic proteins. ERK2 has been shown to play a role inthe negative growth control of breast cancer cells (Frey and Mulder,1997, Cancer Res. 57, 628) and hyperexpression of ERK2 in human breastcancer has been reported (Sivaraman et al., 1997, J. Clin. Invest. 99,1478). Activated ERK2 has also been implicated in the proliferation ofendothelin-stimulated airway smooth muscle cells, suggesting a role forthis kinase in asthma (Whelchel et al., 1997, Am. J. Respir. Cell Mol.Biol. 16, 589).

Overexpression of receptor tyrosine kinases such as EGFR and ErbB2(Arteaga C L, 2002, Semin Oncol. 29, 3-9; Eccles S A, 2001, J MammaryGland Biol Neoplasia 6:393-406; Mendelsohn J & Baselga J, 2000, Oncogene19, 6550-65), as well as activating mutations in the Ras GTPase proteins(Nonage M & Siu L L, 2002, Curr Pharm Des 8, 2231-42; Adjei A A, 2001, JNatl Cancer Inst 93, 1062-74) or B-Raf mutants (Davies H. et al., 2002,Nature 417, 949-54; Brose et al., 2002, Cancer Res 62, 6997-7000) aremajor contributors to human cancer. These genetic alterations arecorrelated with poor clinical prognosis and result in activation of theRaf-1/2/3-MEK1/2-ERK1/2 signal transduction cascade in a broad panel ofhuman tumors. Activated ERK (i.e. ERK1 and/or ERK2) is a centralsignaling molecule that has been associated with the control ofproliferation, differentiation, anchorage-independent cell survival, andangiogenesis, contributing to a number of processes that are importantfor the formation and progression of malignant tumors. These datasuggest that an ERK1/2 inhibitor will exert pleiotropic activity,including proapoptotic, anti-proliferative, anti-metastatic andanti-angiogenic effects, and offer a therapeutic opportunity against avery broad panel of human tumors.

There is a growing body of evidence that implicates constitutiveactivation of the ERK MAPK pathway in the oncogenic behavior of selectcancers. Activating mutations of Ras are found in ˜30% of all cancers,with some, such as pancreatic (90%) and colon (50%) cancer, harboringparticularly high mutation rates (ref). Ras mutations have also beenidentified in 9-15% of melanomas, but B-Raf somatic missense mutationsconferring constitutive activation are more frequent and found in 60-66%malignant melanomas. Activating mutations of Ras, Raf and MEK are ableto oncogenically transform fibroblasts in vitro, and Ras or Rafmutations in conjunction with the loss of a tumor suppressor gene (e.g.p16INK4A) can cause spontaneous tumor development in vivo. Increased ERKactivity has been demonstrated in these models and has also been widelyreported in appropriate human tumors. In melanoma, high basal ERKactivity resulting from either B-Raf or N-Ras mutations or autocrinegrowth factor activation is well documented and has been associated withrapid tumor growth, increased cell survival and resistance to apoptosis.Additionally, ERK activation is considered a major driving force behindthe highly metastatic behavior of melanoma associated with increasedexpression of both extracellular matrix degrading proteases andinvasion-promoting integrins as well as the downregulation of E-cadherinadhesion molecules that normally mediate keratinocyte interactions tocontrol melanocyte growth. These data taken together, indicate ERK aspromising therapeutic target for the treatment of melanoma, a currentlyuntreatable disease.

SUMMARY OF THE INVENTION

It has now been found that compounds of this invention, andpharmaceutically acceptable compositions thereof, are effective asinhibitors of ERK protein kinase. These compounds have the generalformula I:

or a pharmaceutically acceptable salt thereof, wherein m, R¹, R², and R³are as defined below. These compounds, and pharmaceutically acceptablecompositions thereof, are useful for treating or lessening the severityof a variety of disorders, especially proliferative disorders such ascancer.

The compounds provided by this invention are also useful for the studyof kinases in biological and pathological phenomena and the study ofintracellular signal transduction pathways mediated by such kinases, andthe comparative evaluation of new kinase inhibitors.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS OF THE INVENTION

1. General Description of Compounds of the Invention:

The present invention relates to a compound of formula I:

or a pharmaceutically acceptable salt thereof, wherein:

-   R¹ is a C₁₋₆ aliphatic group, wherein R¹ is optionally substituted    with up to 2 groups independently selected from —OR or —C₁₋₃    haloalkyl;-   each R is independently hydrogen or C₁₋₄ aliphatic;-   each R² is independently R, fluoro, or chloro;-   m is 0, 1, or 2; and-   R³ is hydrogen, C₁₋₃ aliphatic, fluoro, or chloro.    2. Compounds and Definitions:

Compounds of this invention include those described generally above, andare further illustrated by the classes, subclasses, and speciesdisclosed herein. As used herein, the following definitions shall applyunless otherwise indicated. For purposes of this invention, the chemicalelements are identified in accordance with the Periodic Table of theElements, CAS version, Handbook of Chemistry and Physics, 75^(th) Ed.Additionally, general principles of organic chemistry are described in“Organic Chemistry”, Thomas Sorrell, University Science Books,Sausalito: 1999, and “March's Advanced Organic Chemistry”, 5^(th) Ed.,Ed.: Smith, M. B. and March, J., John Wiley & Sons, New York: 2001, theentire contents of which are hereby incorporated by reference.

As used herein, the term “prodrug” refers to a derivative of a parentdrug molecule that requires transformation within the body in order torelease the active drug, and that has improved physical and/or deliveryproperties over the parent drug molecule. Prodrugs are designed toenhance pharmaceutically and/or pharmacokinetically based propertiesassociated with the parent drug molecule. The advantage of a prodruglies in its physical properties, such as enhanced water solubility forparenteral administration at physiological pH compared to the parentdrug, or it enhances absorption from the digestive tract, or it mayenhance drug stability for long-term storage. In recent years severaltypes of bioreversible derivatives have been exploited for utilizationin designing prodrugs. Using esters as a prodrug type for drugscontaining carboxyl or hydroxyl function is known in the art asdescribed, for example, in “The Organic Chemistry of Drug Design andDrug Interaction” Richard Silverman, published by Academic Press (1992).

As described herein, compounds of the invention may optionally besubstituted with one or more substituents, such as are illustratedgenerally above, or as exemplified by particular classes, subclasses,and species of the invention. It will be appreciated that the phrase“optionally substituted” is used interchangeably with the phrase“substituted or unsubstituted.” In general, the term “substituted”,whether preceded by the term “optionally” or not, refers to thereplacement of hydrogen radicals in a given structure with the radicalof a specified substituent. Unless otherwise indicated, an optionallysubstituted group may have a substituent at each substitutable positionof the group, and when more than one position in any given structure maybe substituted with more than one substituent selected from a specifiedgroup, the substituent may be either the same or different at everyposition.

Combinations of substituents envisioned by this invention are preferablythose that result in the formation of stable or chemically feasiblecompounds. The term “stable”, as used herein, refers to compounds thatare not substantially altered when subjected to conditions to allow fortheir production, detection, and preferably their recovery,purification, and use for one or more of the purposes disclosed herein.In some embodiments, a stable compound or chemically feasible compoundis one that is not substantially altered when kept at a temperature of40° C. or less, in the absence of moisture or other chemically reactiveconditions, for at least a week.

The term “aliphatic” or “aliphatic group”, as used herein, means astraight-chain (i.e., unbranched) or branched, substituted orunsubstituted hydrocarbon chain that is completely saturated or thatcontains one or more units of unsaturation, or a monocyclic hydrocarbonthat is completely saturated or that contains one or more units ofunsaturation, but which is not aromatic (also referred to herein as“carbocycle” “cycloaliphatic” or “cycloalkyl”), that has a single pointof attachment to the rest of the molecule. In certain embodiments,aliphatic groups contain 1-6 aliphatic carbon atoms, and in yet otherembodiments, aliphatic groups contain 1-4 aliphatic carbon atoms. Insome embodiments, “cycloaliphatic” (or “carbocycle” or “cycloalkyl”)refers to a monocyclic C₃-C₆ hydrocarbon that is completely saturated orthat contains one or more units of unsaturation, but which is notaromatic, that has a single point of attachment to the rest of themolecule. Suitable aliphatic groups include, but are not limited to,linear or branched, substituted or unsubstituted alkyl, alkenyl, alkynylgroups and hybrids thereof such as (cycloalkyl)alkyl,(cycloalkenyl)alkyl or (cycloalkyl)alkenyl.

The term “unsaturated”, as used herein, means that a moiety has one ormore units of unsaturation.

The terms “haloalkyl”, “haloalkenyl” and “haloalkoxy” means alkyl,alkenyl or alkoxy, as the case may be, substituted with one or morehalogen atoms. The term “halogen” means F, Cl, Br, or I.

The term “aryl” used alone or as part of a larger moiety as in“aralkyl”, “aralkoxy”, or “aryloxyalkyl”, refers to monocyclic, bicyclicand tricyclic ring systems having a total of five to fourteen ringmembers, wherein at least one ring in the system is aromatic and whereineach ring in the system contains 3 to 7 ring members. The term “aryl”may be used interchangeably with the term “aryl ring”.

An aryl (including aralkyl, aralkoxy, aryloxyalkyl and the like) orheteroaryl (including heteroaralkyl and heteroarylalkoxy and the like)group may contain one or more substituents. Suitable substituents on theunsaturated carbon atom of an aryl or heteroaryl group are selected fromhalogen; R^(o); OR^(o); SR^(o); 1,2-methylene-dioxy; 1,2-ethylene-dioxy;phenyl (Ph) optionally substituted with R^(o); —O(Ph) optionallysubstituted with R^(o); (CH₂)₁₋₂(Ph), optionally substituted with R^(o);CH═CH(Ph), optionally substituted with R^(o); NO₂; CN; N(R^(o))₂;NR^(o)C(O)R^(o); NR^(o)C(O)N(R^(o))₂; NR^(o)CO₂R^(o);—NR^(o)NR^(o)C(O)R^(o); NR^(o)NR^(o)C(O)N(R^(o))₂; NR^(o)NR^(o)CO₂R^(o);C(O)C(O)R^(o); C(O)CH₂C(O)R^(o); CO₂R^(o); C(O)R^(o); C(O)N(R^(o))₂;OC(O)N(R^(o))₂; S(O)₂R^(o); SO₂N(R^(o))₂; S(O)R^(o); NR^(o)SO₂N(R^(o))₂;NR^(o)SO₂R^(o); C(═S)N(R^(o))₂; C(═NH)—N(R^(o))₂; or (CH₂)₀₋₂NHC(O)R^(o)wherein each independent occurrence of R^(o) is selected from hydrogen,optionally substituted C₁₋₆ aliphatic, an unsubstituted 5-6 memberedheteroaryl or heterocyclic ring, phenyl, O(Ph), or CH₂(Ph), or,notwithstanding the definition above, two independent occurrences ofR^(o), on the same substituent or different substituents, taken togetherwith the atom(s) to which each R^(o) group is bound, form a 3-8 memberedcycloalkyl, heterocyclyl, aryl, or heteroaryl ring having 0-4heteroatoms independently selected from nitrogen, oxygen, or sulfur.Optional substituents on the aliphatic group of R^(o) are selected fromNH₂, NH(C₁₋₄aliphatic), N(C₁₋₄aliphatic)₂, halogen, C₁₋₄aliphatic, OH,O(C₁₋₄aliphatic), NO₂, CN, CO₂H, CO₂(C₁₋₄aliphatic), O(haloC₁₋₄aliphatic), or haloC₁₋₄ aliphatic, wherein each of the foregoingC₁₋₄aliphatic groups of R^(o) is unsubstituted.

An aliphatic or heteroaliphatic group or a non-aromatic heterocyclicring may contain one or more substituents. Suitable substituents on thesaturated carbon of an aliphatic or heteroaliphatic group, or of anon-aromatic heterocyclic ring are selected from those listed above forthe unsaturated carbon of an aryl or heteroaryl group and additionallyinclude the following: ═O, ═S, ═NNHR*, ═NN(R*)₂, ═NNHC(O)R*,═NNHCO₂(alkyl), ═NNHSO₂(alkyl), or ═NR, where each R* is independentlyselected from hydrogen or an optionally substituted C₁₋₆ aliphatic.Optional substituents on the aliphatic group of R* are selected fromNH₂, NH(C₁₋₄ aliphatic), N(C₁₋₄ aliphatic)₂, halogen, C₁₋₄aliphatic, OH,O(C₁₋₄ aliphatic), NO₂, CN, CO₂H, CO₂(C₁₋₄aliphatic), O(halo C₁₋₄aliphatic), or halo(C₁₋₄ aliphatic), wherein each of the foregoingC₁₋₄aliphatic groups of R* is unsubstituted.

Optional substituents on the nitrogen of a non-aromatic heterocyclicring are selected from R⁺, N(R⁺)₂, C(O)R⁺, CO₂R⁺, C(O)C(O)R⁺,C(O)CH₂C(O)R⁺, SO₂R⁺, SO₂N (R⁺)₂, C(═S)N(R⁺)₂, C(═NH)—N(R⁺)₂, orNR⁺SO₂R⁺; wherein R⁺ is hydrogen, an optionally substituted C₁₋₆aliphatic, optionally substituted phenyl, optionally substituted O(Ph),optionally substituted CH₂(Ph), optionally substituted (CH₂)₁₋₂(Ph);optionally substituted CH═CH(Ph); or an unsubstituted 5-6 memberedheteroaryl or heterocyclic ring having one to four heteroatomsindependently selected from oxygen, nitrogen, or sulfur, or,notwithstanding the definition above, two independent occurrences of R⁺,on the same substituent or different substituents, taken together withthe atom(s) to which each R⁺ group is bound, form a 3-8-memberedcycloalkyl, heterocyclyl, aryl, or heteroaryl ring having 0-4heteroatoms independently selected from nitrogen, oxygen, or sulfur.Optional substituents on the aliphatic group or the phenyl ring of R⁺are selected from NH₂, NH(C₁₋₄ aliphatic), N(C₁₋₄ aliphatic)₂, halogen,C₁₋₄ aliphatic, OH, O(C₁₋₄ aliphatic), NO₂, CN, CO₂H, CO₂(C₁₋₄aliphatic), O(halo C₁₋₄ aliphatic), or halo(C₁₋₄ aliphatic), whereineach of the foregoing C₁₋₄aliphatic groups of R⁺ is unsubstituted.

Unless otherwise stated, structures depicted herein are also meant toinclude all isomeric (e.g., enantiomeric, diastereomeric, and geometric(or conformational)) forms of the structure; for example, the R and Sconfigurations for each asymmetric center, (Z) and (E) double bondisomers, and (Z) and (E) conformational isomers. Therefore, singlestereochemical isomers as well as enantiomeric, diastereomeric, andgeometric (or conformational) mixtures of the present compounds arewithin the scope of the invention. Unless otherwise stated, alltautomeric forms of the compounds of the invention are within the scopeof the invention. Additionally, unless otherwise stated, structuresdepicted herein are also meant to include compounds that differ only inthe presence of one or more isotopically enriched atoms. For example,compounds having the present structures except for the replacement ofhydrogen by deuterium or tritium, or the replacement of a carbon by a¹³C- or ¹⁴C-enriched carbon are within the scope of this invention. Suchcompounds are useful, for example, as analytical tools or probes inbiological assays.

3. Description of Exemplary Compounds:

According to one embodiment, the present invention relates to a compoundof formula I wherein said compound is of formula Ia or Ib:

or a pharmaceutically acceptable salt thereof, wherein each m, R¹, R²,and R³ group is as defined above.

According to certain embodiments, the R¹ moiety of any of formulae I,Ia, and Ib, is C₁₋₄ aliphatic optionally substituted with —OR or —C₁₋₃haloalkyl. In certain embodiments, the R¹ moiety of any of formulae I,Ia, and Ib is C₁₋₄ aliphatic optionally substituted with —OH, —CH₂F,—CHF₂, or —CF₃. In other embodiments, the R¹ moiety of any of formulaeI, la, and lb is C₁₋₄ aliphatic optionally substituted with —OH. In yetother embodiments, R¹ is unsubstituted.

According to another embodiment, the R¹ moiety of any of formulae I, Ia,and lb is isopropyl, 2-butyl, cyclopropyl, or ethyl, wherein each moietyis optionally substituted with —OH, —CHF₂, —CH₂F, or —CF₃. In certainembodiments, the R¹ moiety of any of formulae I, Ia, and Ib isoptionally substituted with —OH or —CF₃.

Another aspect of the present invention relates to a compound of any offormulae I, Ia, and Ib wherein R² is hydrogen, C₁₋₃ aliphatic, orchloro. According to yet another aspect, the present invention relatesto a compound of any of formulae I, Ia, and Ib wherein R² is chloro.

In certain embodiments, m is 1.

In other embodiments, the R³ moiety of any of formulae I, Ia, and Ib ishydrogen, methyl, or chloro.

Representative compounds of formula I are set forth in Table 1 below.

TABLE 1 Examples of Compounds of Formula I:

I-1

I-2

I-3

I-4

I-5

I-6

I-7

I-8

I-9

I-10

I-11

I-12

I-13

I-14

I-15

I-16

I-17

I-184. General Methods of Providing the Present Compounds:

The compounds of this invention may be prepared or isolated in generalby synthetic and/or pseudo-synthetic methods known to those skilled inthe art for analogous compounds and as illustrated by the generalSchemes I, II and III below and the preparative examples that follow.

General Scheme I above shows a general method for preparing thecompounds of the present invention. At step (a), the pyrrole compound 1is iodinated and esterified to form 2. At step (b), the pyrrole moietyis optionally protected at the —NH— with a suitable amino protectinggroup to form 3. Amino protecting groups are well known in the art andare described in detail in Protecting Groups in Organic Synthesis.Theodora W. Greene and Peter G. M. Wuts, 1991, published by John Wileyand Sons, the entirety of which is hereby incorporated by reference. Theiodo moiety of compound 3 is displaced by an appropriate boronic acid orester. As depicted above, bis(pinacolato)diborane is used to formcompound 4 however other boronic esters or acids are amenable to thisreaction and would be apparent to one of ordinary skill in the art.

Because the present compounds relate to a multi-substituted pyridinemoiety, the order of reaction is considered and methods of activatingpositions on the pyridine are utilized to direct the regiochemistry. Instep (d) above, the first leaving group L¹ may be displaced by analcohol, amine or thiol as desired. One of ordinary skill in the artwould recognize that various L¹ leaving groups are amenable to thisreaction. Examples of such groups include, but are not limited to,halogen and activated ethers. This reaction may be followed, at step(e), by the replacement of a second leaving group L² through either ametal catalyzed coupling reaction or a nucleophilic displacement to formcompound 7. One of ordinary skill in the art would recognize thatvarious L² leaving groups are amenable to this reaction. Examples ofsuch groups include, but are not limited to, halogen, activated ethers,boronic acid, or boronic ester.

At step (f), the protecting group on the pyrrole moiety is removed bymethods suitable for removing the amino protecting group used. Dependingon which amino protecting group is used, the conditions suitable forremoving it may simultaneously saponify or otherwise provide thecarboxylate moiety as depicted above for compound 8. If the conditionssuitable for removing the amino protecting group are not suitable forproviding the carboxylate compound 8, then another step may be employed.Compounds of formula 1 are prepared from 8 by coupling the resultingcarboxylate with a desired amine as depicted at step (g). One ofordinary skill in the art would recognize that a variety of conditionsare useful for said coupling reaction and can include the step ofactivating the carboxylate moiety of compound 8 prior to orsimultaneously with treatment with the desired amine. Such conditionsinclude, but are not limited to, those described in detail in theExamples section below.

Scheme II above depicts an alternate route to prepare intermediatecompound 6 useful for preparing compounds of the present invention. Atstep (a), the N-oxide of compound 9 is prepared by treatment withperoxide. The N-oxide compound 10 is then treated with nitric acid toform the nitro compound 11. The L¹ group of 11 is displaced with thedesired amine R¹—NH₂ to form 12 and then the L² group is introduced atstep (d) to afford intermediate 6. Compound 6 may then be utilized toprepare compounds of the present invention according to the generalScheme I above and the Examples provided below.

Scheme III above shows an alternate method for preparing compound 7 from6. In this method, the L² group of the pyridinyl compound 6 is displacedby an appropriate boronic acid or ester derivative to form 13, whereinR^(x) and R_(y) have the meanings as defined for compounds of formula Ainfra. This boronate moiety is then displaced by the L³ leaving group ofthe pyrrole depicted above, wherein L³ is a suitable leaving group, toform compound 7. Compound 7 is then used to prepare compounds of thepresent invention by methods set forth above in Schemes I and II, bythose described in the Examples section and by methods known to one ofordinary skill in the art.

One of skill in the art would recognize that a variety of compounds ofthe present invention may be prepared according to the general method ofSchemes I, II and III, and the synthetic Examples set forth below.

According to another embodiment, the present invention relates to acompound of formula A:

or a salt thereof, wherein:

-   PG is a suitable amino protecting group;-   R^(z) is a suitable carboxylate protecting group; and-   R^(x) and R^(y) are independently hydrogen or optionally substituted    C₁₋₆ aliphatic, or:    -   R^(x) and R^(y) are taken together to form an optionally        substituted 5-7 membered ring.

Suitable amino protecting groups are well known in the art and includethose described in detail in Protecting Groups in Organic Synthesis,Theodora W. Greene and Peter G. M. Wuts, 1991, published by John Wileyand Sons. In certain embodiments, the PG group of A is an alkyl or arylsulfonyl moiety. Examples of such groups include mesyl, tosyl, nosyl,brosyl, and 2,4,6-trimethylbenzenesulfonyl (“Mts”). Other such groupsinclude Bn, PMB, Ms, Ts, SiR₃, MOM, BOM, Tr, Ac, CO₂R,CH₂OCH₂CH₂Si(CH₃)₃.

Suitable carboxylate protecting groups are well known in the art and aredescribed in detail in Protecting Groups in Organic Synthesis, TheodoraW. Greene and Peter G. M. Wuts, 3^(rd) Edition, 1999, published by JohnWiley and Sons. In certain embodiments, the R^(z) group of A is anoptionally substituted C₁₋₆ aliphatic group or an optionally substitutedaryl group. Examples of suitable R^(z) groups include methyl, ethyl,propyl, isopropyl, butyl, isobutyl, benzyl, and phenyl wherein eachgroup is optionally substituted.

In certain embodiments, one or both of R^(x) and R^(y) are hydrogen.

In other embodiments, R^(x) and R^(y) are taken together to form anoptionally substituted 5-6 membered ring. In yet other embodiments,R^(x) and R^(y) are taken together to form a4,4,5,5-tetramethyldioxaborolane moiety. Other suitable boronatederivatives contemplated by the present invention include boronic acid,B(O—C₁₋₁₀ aliphatic)₂, and B(O-Aryl)₂.

According to yet another embodiment, the present invention provides acompound of formula B:

or a salt thereof, wherein:

-   R¹ is a C₁₋₆ aliphatic group, wherein R¹ is optionally substituted    with up to 2 groups independently selected from —OR or —C₁₋₃    haloalkyl;-   each R is independently hydrogen or C₁₋₄ aliphatic;-   R³ is hydrogen, C₁₋₃ aliphatic, fluoro, or chloro; and-   L² is a suitable leaving group.

In certain embodiments, the present invention provides a compound offormula B, as defined generally and in classes and subclasses describedabove and herein, wherein L² is not iodo when R³ is chloro and R¹ isisopropyl.

A suitable leaving group is a chemical group that is readily displacedby a desired incoming chemical moiety. Thus, the choice of the specificsuitable leaving group is predicated upon its ability to be readilydisplaced by the incoming chemical moiety of formula A. Suitable leavinggroups are well known in the art, e.g., see, “Advanced OrganicChemistry,” Jerry March, 5^(th) Ed., pp. 351-357, John Wiley and Sons,N.Y. Such leaving groups include, but are not limited to, halogen,alkoxy, sulphonyloxy, optionally substituted alkylsulphonyl, optionallysubstituted alkenylsulfonyl, optionally substituted arylsulfonyl, anddiazonium moieties. Examples of suitable leaving groups include chloro,iodo, bromo, fluoro, methanesulfonyl (mesyl), tosyl, triflate,nitro-phenylsulfonyl (nosyl), and bromo-phenylsulfonyl (brosyl). Incertain embodiments, the L² moiety of B is iodo.

According to an alternate embodiment, the suitable leaving group may begenerated in situ within the reaction medium. For example, L² in acompound of formula B may be generated in situ from a precursor of thatcompound of formula B wherein said precursor contains a group readilyreplaced by L² in situ. In a specific illustration of such areplacement, said precursor of a compound of formula B contains a group(for example, a chloro group or hydroxyl group) which is replaced insitu by L², such as an iodo group. The source of the iodo group may be,e.g., sodium iodide. Such an in situ generation of a suitable leavinggroup is well known in the art, e.g., see, “Advanced Organic Chemistry,”Jerry March, pp. 430-431, 5^(th) Ed., John Wiley and Sons, N.Y.

According to certain embodiments, the R¹ moiety of formula B, is C₁₋₄aliphatic optionally substituted with —OR or —C₁₋₃ haloalkyl. In certainembodiments, the R¹ moiety of formula B is C¹⁻⁴ aliphatic optionallysubstituted with —OH, —CH₂F, —CHF₂, or —CF₃. In other embodiments, theR¹ moiety of formula B is C₁₋₄ aliphatic optionally substituted with—OH. In yet other embodiments, R¹ is unsubstituted.

According to another embodiment, the R¹ moiety of formula B isisopropyl, 2-butyl, cyclopropyl, or ethyl, wherein each moiety isoptionally substituted with —OH or —CF₃.

In other embodiments, the R³ moiety of formula B is hydrogen, methyl, orchloro.

A compound of formula B may be prepared from a compound of formula B′:

or a salt thereof, wherein:

-   R³ is hydrogen, C₁₋₃ aliphatic, fluoro, or chloro; and-   L¹ and L² are each independently a suitable leaving group.

In certain embodiments, the present invention provides a compound offormula B′, as defined generally and in classes and subclasses describedabove and herein, wherein L² is not a boronate moiety when R³ is chloroand R¹ is fluoro.

In certain embodiments, a compound of B′ is provided wherein L² is—B(OR^(x))(OR^(y)). In other embodiments, one or both of R^(x) and R^(y)are hydrogen. In other embodiments, R^(x) and R^(y) are taken togetherto form an optionally substituted 5-6 membered ring. In yet otherembodiments, R^(x) and R^(y) are taken together to form a4,4,5,5-tetramethyldioxaborolane moiety.

As described above, a suitable leaving group is a chemical group that isreadily displaced by a desired incoming chemical moiety. Suitableleaving groups are well known in the art, e.g., see, “Advanced OrganicChemistry,” Jerry March, 5^(th) Ed., pp. 351-357, John Wiley and Sons,N.Y. Such leaving groups include, but are not limited to, halogen,alkoxy, sulphonyloxy, optionally substituted alkylsulphonyl, optionallysubstituted alkenylsulfonyl, optionally substituted arylsulfonyl, anddiazonium moieties. Examples of suitable leaving groups include chloro,iodo, bromo, fluoro, methanesulfonyl (mesyl), tosyl, triflate,nitro-phenylsulfonyl (nosyl), and bromo-phenylsulfonyl (brosyl). Incertain embodiments, the L¹ moiety of B′ is halogen. In otherembodiment, the L¹ moiety of B′ is an optionally substitutedalkylsulphonyl, optionally substituted alkenylsulfonyl, or optionallysubstituted arylsulfonyl group. In other embodiments, the L¹ moiety ofB′ is fluoro.

According to an alternate embodiment, the suitable leaving group may begenerated in situ within the reaction medium. For example, L¹ or L²moieties in a compound of formula B′may be generated in situ from aprecursor of that compound of formula B′ wherein said precursor containsa group readily replaced by L¹ or L² in situ. Such an in situ generationof a suitable leaving group is well known in the art, e.g., see,“Advanced Organic Chemistry,” Jerry March, pp. 430-431, 5^(th) Ed., JohnWiley and Sons, N.Y.

According to another embodiment, the present invention provides a methodfor preparing a compound of formula B:

or a salt thereof, comprising the step of reacting a compound of formulaB′:

or a salt thereof, with a compound of formula R¹—NH₂ wherein saidreaction is performed in a suitable medium and wherein:

-   R¹ is a C₁₋₆ aliphatic group, wherein R¹ is optionally substituted    with up to 2 groups independently selected from —OR or —C₁₋₃    haloalkyl;-   R is hydrogen or C₁₋₄ aliphatic;-   R³ is hydrogen, C₁₋₃ aliphatic, fluoro, or chloro; and-   L¹ and L² are each independently a suitable leaving group.

In certain embodiments, said reaction is optionally performed in thepresence of a suitable base. One of ordinary skill would recognize thatthe displacement of a leaving group by an amino moiety is achievedeither with or without the presence of a suitable base. Such suitablebases are well known in the art and include organic and inorganic bases.

A suitable medium is a solvent or a solvent mixture that, in combinationwith the combined compounds, may facilitate the progress of the reactiontherebetween. The suitable solvent may solubilize one or more of thereaction components, or, alternatively, the suitable solvent mayfacilitate the agitation of a suspension of one or more of the reactioncomponents. Examples of suitable solvents useful in the presentinvention are a protic solvent, a halogenated hydrocarbon, an ether, anaromatic hydrocarbon, a polar or a non-polar aprotic solvent, or anymixtures thereof. Such mixtures include, for example, mixtures of proticand non-protic solvents such as benzene/methanol/water; benzene/water;DME/water, and the like.

These and other such suitable solvents are well known in the art, e.g.,see, “Advanced Organic Chemistry”, Jerry March, 5^(th) edition, JohnWiley and Sons, N.Y.

According to yet another embodiment, one or more reagents may perform asthe suitable solvent. For example, an organic base such as triethylamineor diisopropylethylamine, if utilized in said reaction, may serve as thesolvent in addition to its role as a basifying reagent.

In certain embodiments, the present invention provides a compound offormula B′ wherein R¹ and R³ are as defined generally and in classes andsubclasses described above and herein.

According to another aspect, the present invention provides a compoundof formula C:

or a salt thereof, wherein:

-   PG is a suitable amino protecting group;-   R^(z) is a suitable carboxylate protecting group;-   R¹ is a C₁₋₆ aliphatic group, wherein R¹ is optionally substituted    with up to 2 groups independently selected from —OR or —C₁₋₃    haloalkyl;-   each R is independently hydrogen or C₁₋₄ aliphatic; and-   R³ is hydrogen, C₁₋₃ aliphatic, fluoro, or chloro.

As noted above, suitable amino protecting groups are well known in theart and include those described in detail in Protecting Groups inOrganic Synthesis, Theodora W. Greene and Peter G. M. Wuts, 1991,published by John Wiley and Sons. In certain embodiments, the PG groupof C is an alkyl or aryl sulfonyl moiety. Examples of such groupsinclude mesyl, tosyl, nosyl, brosyl, and 2,4,6-trimethylbenzenesulfonyl(“Mts”).

Suitable carboxylate protecting groups are well known in the art and aredescribed in detail in Protecting Groups in Organic Synthesis, TheodoraW. Greene and Peter G. M. Wuts, 1991, published by John Wiley and Sons.In certain embodiments, the R^(z) group of C is an optionallysubstituted C₁₋₆ aliphatic group or an optionally substituted arylgroup. Examples of suitable R^(z) groups include methyl, ethyl, propyl,isopropyl, butyl, isobutyl, benzyl, and phenyl wherein each group isoptionally substituted.

According to certain embodiments, the R¹ moiety of formula C, is C₁₋₄aliphatic optionally substituted with —OR or —C₁₋₃ haloalkyl. In certainembodiments, the R¹ moiety of formula C is C₁₋₄ aliphatic optionallysubstituted with —OH, —CH₂F, —CHF₂, or —CF₃. In other embodiments, theR¹ moiety of formula C is C₁₋₄ aliphatic optionally substituted with—OH. In yet other embodiments, R¹ is unsubstituted.

According to another embodiment, the R¹ moiety of formula C isisopropyl, 2-butyl, cyclopropyl, or ethyl, wherein each moiety isoptionally substituted with —OH or —CF₃.

In other embodiments, the R³ moiety of formula C is hydrogen, methyl, orchloro.

Yet another aspect of the present invention relates to a method forpreparing a compound of formula C:

or a salt thereof, comprising the step of reacting a compound of formulaA:

or a salt thereof, with a compound of formula B:

or a salt thereof, wherein said reaction is performed in a suitablemedium and wherein:

-   PG is a suitable amino protecting group;-   L² is a suitable leaving group.-   R^(z) is a suitable carboxylate protecting group;-   R^(x) and R^(y) are independently hydrogen or optionally substituted    C₁₋₆ aliphatic, or:    -   R^(x) and R^(y) are taken together to form an optionally        substituted 5-7 membered ring;-   R¹ is a C₁₋₆ aliphatic group, wherein R¹ is optionally substituted    with up to 2 groups independently selected from —OR or —C₁₋₃    haloalkyl;-   each R is independently hydrogen or C₁₋₄ aliphatic; and-   R³ is hydrogen, C₁₋₃ aliphatic, fluoro, or chloro.

In certain embodiments, said reaction is performed in the presence of Ni(II), Pd (O), or Pd(II) where each catalyst may be associated with aligand such as ferrocene or phosphine based ligands. In otherembodiments, said reaction is performed in the presence of Pd(PPh₃)₄. Asuitable medium is a solvent or a solvent mixture that, in combinationwith the combined compounds, may facilitate the progress of the reactiontherebetween. The suitable solvent may solubilize one or more of thereaction components, or, alternatively, the suitable solvent mayfacilitate the agitation of a suspension of one or more of the reactioncomponents. Examples of suitable solvents useful in the presentinvention are a protic solvent, a halogenated hydrocarbon, an ether, anaromatic hydrocarbon, a polar or a non-polar aprotic solvent, or anymixtures thereof. Such mixtures include, for example, mixtures of proticand non-protic solvents such as benzene/methanol/water; benzene/water;DME/water, and the like.

These and other such suitable solvents are well known in the art, e.g.,see, “Advanced Organic Chemistry”, Jerry March, 5^(th) edition, JohnWiley and Sons, N.Y.

In certain embodiments, the reaction between compounds A and B to form Cis performed in a mixture of DME and water.

In certain embodiments, the reaction between compounds A and B to form Cis performed at a temperature ranging from about 20° C. to 150° C. Inother embodiments, the reaction between compounds A and B to form C isperformed with microwave irradiation at a temperature ranging from about100° C. to 250° C.

In still other embodiments, the reaction between compounds A and B toform C is performed at a somewhat basic pH.

According to another embodiment, the present invention provides aprodrug of a compound of formula 1 wherein said prodrug is of formulaII:

or a pharmaceutically acceptable salt thereof, wherein:

-   R¹ is a C₁₋₆ aliphatic group, wherein R¹ is optionally substituted    with up to 2 groups independently selected from —OR, —OR⁴, or —C₁₋₃    haloalkyl;-   each R is independently hydrogen or a C₁₋₆ aliphatic;-   each R² is independently R, fluoro, or chloro;-   m is 0, 1, or 2;-   R³ is hydrogen, C₁₋₃ aliphatic, fluoro, or chloro;-   each R⁴ is independently hydrogen, —C(R)₂O—R⁵, or R⁵, provided that    at least one R⁴ or R⁸ group is other than hydrogen;-   each R⁵ is independently —C(O)R⁶, —C(O)OR⁶, —C(O)-Q-R⁶,    —C(O)—(CH₂)_(n)—C(O)OR⁶, —C(O)—(CH₂)_(n)—C(O)N(R⁷)₂,    —C(O)—(CH₂)_(n)—CH(R⁶)N(R⁷)₂, —P(O) (OR⁶)₂;-   each R⁶ is independently hydrogen, an optionally substituted C₁₋₆    aliphatic group or an optionally substituted 5-8 membered saturated,    partially unsaturated, or fully unsaturated ring having 0-4    heteroatoms independently selected from nitrogen, oxygen, or sulfur;-   each R⁷ is independently hydrogen, —C(O)R⁶, —C(O)OR⁶, —S(O)₂R⁶,    —OR⁶, an optionally substituted C₁₋₆ aliphatic group or an    optionally substituted 5-8 membered saturated, partially    unsaturated, or fully unsaturated ring having 0-4 heteroatoms    independently selected from nitrogen, oxygen, or sulfur, or:    -   two R⁶ on the same nitrogen atom taken together with the        nitrogen atom bound thereto form a 4-7 membered saturated,        partially unsaturated, or fully unsaturated ring having 1-3        heteroatoms in addition to the nitrogen atom, independently        selected from nitrogen, oxygen, or sulfur;-   each n is 0-6;-   Q is an optionally substituted C₁₋₁₀ alkylidene chain wherein zero    to four methylene units of Q are independently replaced by —O—,    —N(R)—, —S—, —S(O)—, —S(O)₂—, or —C(O)—; and-   R⁸ is hydrogen or —C(R)₂O—R⁵.

According to certain embodiments, the R¹ moiety of formula II is C₁₋₄aliphatic optionally substituted with —OR or —C₁₋₃ haloalkyl. In certainembodiments, the R¹ moiety of formula II is C₁₋₄ aliphatic optionallysubstituted with —OH, —CH₂F, —CHF₂, or —CF₃. In other embodiments, theR¹ moiety of formula II is C₁₋₄ aliphatic optionally substituted with—OH. In yet other embodiments, R¹ is unsubstituted.

According to another embodiment, the R¹ moiety of formula II isisopropyl, 2-butyl, cyclopropyl, or ethyl, wherein each moiety isoptionally substituted with —OH, —CHF₂, —CH₂F, or —CF₃. According to yetanother embodiment, the R¹ moiety of formula II is isopropyl, 2-butyl,cyclopropyl, or ethyl, wherein each moiety is optionally substitutedwith —OH or —CF₃.

Another aspect of the present invention relates to a compound of formulaII wherein each R² is independently hydrogen, C₁₋₃ aliphatic, or chloro.According to yet another aspect, the present invention relates to acompound of formula II wherein R² is chloro and m is 1.

In other embodiments, the R³ moiety of formula II is hydrogen, methyl,or chloro.

In certain embodiments, R⁴ is C(O)-Q-R⁶. Still other embodiments relatedto a compound of formula II wherein R⁴ is C(O)-Q-R⁶ and Q is anoptionally substituted C₁₋₈ alkylidene chain wherein zero to fourmethylene units of Q are independently replaced by —O—, —N(R)—, —S—,—S(O)—, —S(O)₂—, or —C(O)— and R⁶ is as defined in general and inclasses and subclasses described above and herein. According to anotherembodiment, Q is an optionally substituted C₁₋₈ alkylidene chain whereintwo to four methylene units of Q are independently replaced by —O—. SuchQ groups include —CH₂OCH₂CH₂O—, —CH₂OCH₂CH₂OCH₂CH₂O—, and the like.

Yet another aspect of the present invention provides a compound offormula II wherein R⁴ is C(O)—(CH₂)_(n)—CH (R⁶)N(R⁷)₂. In certainembodiments, n is 0-2. In other embodiments, R⁶ is an optionallysubstituted C₁₋₆ aliphatic group. Examples of such R⁶ groups includemethyl, benzyl, ethyl, isopropyl, t-butyl, and the like. The R⁷ groupsof the C(O)—(CH₂)_(n)—CH(R⁶)N(R⁷)₂ of formula II include hydrogen and anoptionally substituted C₁₋₆ aliphatic group. Examples of such groupsinclude methyl, benzyl, ethyl, isopropyl, t-butyl, and the like.

According to one aspect, the present invention provides a compound offormula II wherein R⁸ is hydrogen.

According to one embodiment, R⁴ is an L-valine ester.

In certain embodiments of the present invention, the R⁴ group of formulaII is —P(O)(OR⁶)₂. In other embodiments, each R⁶ is independentlyhydrogen or an optionally substituted C₁₋₆ aliphatic group. Examples ofsuch R⁶ groups include methyl, benzyl, ethyl, isopropyl, t-butyl, andthe like. In still other embodiments, the R⁴ group of formula II is—P(O)(OH)₂.

In certain embodiments, a compound of formula II provides improvementwith regard to one or more physical or physiological characteristics. Inother embodiments, a compound of formula II imparts improvement withregard to one or more physical and physiological characteristics.

Representative compounds of formula II are set forth in Table 2 below.

TABLE 2

II-1

II-2

II-3

II-4

II-5

II-6

II-7

II-8

Methods of preparing such prodrugs include those set Forth in detail inthe Examples section infra and methods known to one or ordinary skill inthe art.

5. Uses, Formulation and Administration

Pharmaceutically Acceptable Compositions

As discussed above, the present invention provides compounds that areinhibitors of protein kinases, and thus the present compounds are usefulfor the treatment of diseases, disorders, and conditions including, butnot limited to cancer, autoimmune disorders, neurodegenerative andneurological disorders, schizophrenia, bone-related disorders, liverdisease, and cardiac disorders. Accordingly, in another aspect of thepresent invention, pharmaceutically acceptable compositions areprovided, wherein these compositions comprise any of the compounds asdescribed herein, and optionally comprise a pharmaceutically acceptablecarrier, adjuvant or vehicle. In certain embodiments, these compositionsoptionally further comprise one or more additional therapeutic agents.

It will also be appreciated that certain of the compounds of presentinvention can exist in free form for treatment, or where appropriate, asa pharmaceutically acceptable derivative thereof. According to thepresent invention, a pharmaceutically acceptable derivative includes,but is not limited to, pharmaceutically acceptable salts, esters, saltsof such esters, or any other adduct or derivative which uponadministration to a patient in need is capable of providing, directly orindirectly, a compound as otherwise described herein, or a metabolite orresidue thereof.

As used herein, the term “pharmaceutically acceptable salt” refers tothose salts which are, within the scope of sound medical judgment,suitable for use in contact with the tissues of humans and lower animalswithout undue toxicity, irritation, allergic response and the like, andare commensurate with a reasonable benefit/risk ratio. A“pharmaceutically acceptable salt” means any non-toxic salt or salt ofan ester of a compound of this invention that, upon administration to arecipient, is capable of providing, either directly or indirectly, acompound of this invention or an inhibitorily active metabolite orresidue thereof. As used herein, the term “inhibitorily activemetabolite or residue thereof” means that a metabolite or residuethereof is also an inhibitor of ERK2 protein kinase.

Pharmaceutically acceptable salts are well known in the art. Forexample, S. M. Berge et al., describe pharmaceutically acceptable saltsin detail in J. Pharmaceutical Sciences, 1977, 66, 1-19, incorporatedherein by reference. Pharmaceutically acceptable salts of the compoundsof this invention include those derived from suitable inorganic andorganic acids and bases. Examples of pharmaceutically acceptable,nontoxic acid addition salts are salts of an amino group formed withinorganic acids such as hydrochloric acid, hydrobromic acid, phosphoricacid, sulfuric acid and perchloric acid or with organic acids such asacetic acid, oxalic acid, maleic acid, tartaric acid, citric acid,succinic acid or malonic acid or by using other methods used in the artsuch as ion exchange. Other pharmaceutically acceptable salts includeadipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate,bisulfate, borate, butyrate, camphorate, camphorsulfonate, citrate,cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate,formate, fumarate, glucoheptonate, glycerophosphate, gluconate,hemisulfate, heptanoate, hexanoate, hydroiodide,2-hydroxy-ethanesulfonate, lactobionate, lactate, laurate, laurylsulfate, malate, maleate, malonate, methanesulfonate,2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate,pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate,pivalate, propionate, stearate, succinate, sulfate, tartrate,thiocyanate, p-toluenesulfonate, undecanoate, valerate salts, and thelike. Salts derived from appropriate bases include alkali metal,alkaline earth metal, ammonium and N⁺(C₁₋₄ alkyl)₄ salts. This inventionalso envisions the quaternization of any basic nitrogen-containinggroups of the compounds disclosed herein. Water or oil-soluble ordispersable products may be obtained by such quaternization.Representative alkali or alkaline earth metal salts include sodium,lithium, potassium, calcium, magnesium, and the like. Furtherpharmaceutically acceptable salts include, when appropriate, nontoxicammonium, quaternary ammonium, and amine cations formed usingcounterions such as halide, hydroxide, carboxylate, sulfate, phosphate,nitrate, loweralkyl sulfonate and aryl sulfonate.

As described above, the pharmaceutically acceptable compositions of thepresent invention additionally comprise a pharmaceutically acceptablecarrier, adjuvant, or vehicle, which, as used herein, includes any andall solvents, diluents, or other liquid vehicle, dispersion orsuspension aids, surface active agents, isotonic agents, thickening oremulsifying agents, preservatives, solid binders, lubricants and thelike, as suited to the particular dosage form desired. Remington'sPharmaceutical Sciences, Sixteenth Edition, E. W. Martin (MackPublishing Co., Easton, Pa., 1980) discloses various carriers used informulating pharmaceutically acceptable compositions and knowntechniques for the preparation thereof. Except insofar as anyconventional carrier medium is incompatible with the compounds of theinvention, such as by producing any undesirable biological effect orotherwise interacting in a deleterious manner with any othercomponent(s) of the pharmaceutically acceptable composition, its use iscontemplated to be within the scope of this invention. Some examples ofmaterials which can serve as pharmaceutically acceptable carriersinclude, but are not limited to, ion exchangers, alumina, aluminumstearate, lecithin, serum proteins, such as human serum albumin, buffersubstances such as phosphates, glycine, sorbic acid, or potassiumsorbate, partial glyceride mixtures of saturated vegetable fatty acids,water, salts or electrolytes, such as protamine sulfate, disodiumhydrogen phosphate, potassium hydrogen phosphate, sodium chloride, zincsalts, colloidal silica, magnesium trisilicate, polyvinyl pyrrolidone,polyacrylates, waxes, polyethylene-polyoxypropylene-block polymers, woolfat, sugars such as lactose, glucose and sucrose; starches such as cornstarch and potato starch; cellulose and its derivatives such as sodiumcarboxymethyl cellulose, ethyl cellulose and cellulose acetate; powderedtragacanth; malt; gelatin; talc; excipients such as cocoa butter andsuppository waxes; oils such as peanut oil, cottonseed oil; saffloweroil; sesame oil; olive oil; corn oil and soybean oil; glycols; such apropylene glycol or polyethylene glycol; esters such as ethyl oleate andethyl laurate; agar; buffering agents such as magnesium hydroxide andaluminum hydroxide; alginic acid; pyrogen-free water; isotonic saline;Ringer's solution; ethyl alcohol, and phosphate buffer solutions, aswell as other non-toxic compatible lubricants such as sodium laurylsulfate and magnesium stearate, as well as coloring agents, releasingagents, coating agents, sweetening, flavoring and perfuming agents,preservatives and antioxidants can also be present in the composition,according to the judgment of the formulator.

Uses of Compounds and Pharmaceutically Acceptable Compositions

In yet another aspect, a method for the treatment or lessening theseverity of cancer, an autoimmune disorder, a neurodegenerative orneurological disorder, liver disease, or a cardiac disorder is providedcomprising administering an effective amount of a compound of thepresent invention, or a pharmaceutically acceptable compositioncomprising a compound of the present invention to a subject in needthereof. In certain embodiments of the present invention an “effectiveamount” of the compound or pharmaceutically acceptable composition isthat amount effective for treating or lessening the severity of adisease, condition, or disorder selected from cancer, an autoimmunedisorder, a neurodegenerative or neurological disorder, schizophrenia, abone-related disorder, liver disease, or a cardiac disorder. Thecompounds and compositions, according to the method of the presentinvention, may be administered using any amount and any route ofadministration effective for treating or lessening the severity ofcancer, an autoimmune disorder, a neurodegenerative or neurologicaldisorder, schizophrenia, a bone-related disorder, liver disease, or acardiac disorder. The exact amount required will vary from subject tosubject, depending on the species, age, and general condition of thesubject, the severity of the infection, the particular agent, its modeof administration, and the like. The compounds of the invention arepreferably formulated in dosage unit form for ease of administration anduniformity of dosage. The expression “dosage unit form” as used hereinrefers to a physically discrete unit of agent appropriate for thepatient to be treated. It will be understood, however, that the totaldaily usage of the compounds and compositions of the present inventionwill be decided by the attending physician within the scope of soundmedical judgment. The specific effective dose level for any particularpatient or organism will depend upon a variety of factors including thedisorder being treated and the severity of the disorder; the activity ofthe specific compound employed; the specific composition employed; theage, body weight, general health, sex and diet of the patient; the timeof administration, route of administration, and rate of excretion of thespecific compound employed; the duration of the treatment; drugs used incombination or coincidental with the specific compound employed, andlike factors well known in the medical arts. The term “patient”, as usedherein, means an animal, preferably a mammal, and most preferably ahuman.

The pharmaceutically acceptable compositions of this invention can beadministered to humans and other animals orally, rectally, parenterally,intracisternally, intravaginally, intraperitoneally, topically (as bypowders, ointments, or drops), bucally, as an oral or nasal spray, orthe like, depending on the severity of the infection being treated. Incertain embodiments, the compounds of the invention may be administeredorally or parenterally at dosage levels of about 0.01 mg/kg to about 50mg/kg and preferably from about 1 mg/kg to about 25 mg/kg, of subjectbody weight per day, one or more times a day, to obtain the desiredtherapeutic effect.

Liquid dosage forms for oral administration include, but are not limitedto, pharmaceutically acceptable emulsions, microemulsions, solutions,suspensions, syrups and elixirs. In addition to the active compounds,the liquid dosage forms may contain inert diluents commonly used in theart such as, for example, water or other solvents, solubilizing agentsand emulsifiers such as ethyl alcohol, isopropyl alcohol, ethylcarbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propyleneglycol, 1,3-butylene glycol, dimethylformamide, oils (in particular,cottonseed, groundnut, corn, germ, olive, castor, and sesame oils),glycerol, tetrahydrofurfuryl alcohol, polyethylene glycols and fattyacid esters of sorbitan, and mixtures thereof. Besides inert diluents,the oral compositions can also include adjuvants such as wetting agents,emulsifying and suspending agents, sweetening, flavoring, and perfumingagents.

Injectable preparations, for example, sterile injectable aqueous oroleaginous suspensions may be formulated according to the known artusing suitable dispersing or wetting agents and suspending agents. Thesterile injectable preparation may also be a sterile injectablesolution, suspension or emulsion in a nontoxic parenterally acceptablediluent or solvent, for example, as a solution in 1,3-butanediol. Amongthe acceptable vehicles and solvents that may be employed are water,Ringer's solution, U.S.P. and isotonic sodium chloride solution. Inaddition, sterile, fixed oils are conventionally employed as a solventor suspending medium. For this purpose any bland fixed oil can beemployed including synthetic mono- or diglycerides. In addition, fattyacids such as oleic acid are used in the preparation of injectables.

The injectable formulations can be sterilized, for example, byfiltration through a bacterial-retaining filter, or by incorporatingsterilizing agents in the form of sterile solid compositions which canbe dissolved or dispersed in sterile water or other sterile injectablemedium prior to use.

In order to prolong the effect of a compound of the present invention,it is often desirable to slow the absorption of the compound fromsubcutaneous or intramuscular injection. This may be accomplished by theuse of a liquid suspension of crystalline or amorphous material withpoor water solubility. The rate of absorption of the compound thendepends upon its rate of dissolution that, in turn, may depend uponcrystal size and crystalline form. Alternatively, delayed absorption ofa parenterally administered compound form is accomplished by dissolvingor suspending the compound in an oil vehicle. Injectable depot forms aremade by forming microencapsule matrices of the compound in biodegradablepolymers such as polylactide-polyglycolide. Depending upon the ratio ofcompound to polymer and the nature of the particular polymer employed,the rate of compound release can be controlled. Examples of otherbiodegradable polymers include poly(orthoesters) and poly(anhydrides).Depot injectable formulations are also prepared by entrapping thecompound in liposomes or microemulsions that are compatible with bodytissues.

Compositions for rectal or vaginal administration are preferablysuppositories which can be prepared by mixing the compounds of thisinvention with suitable non-irritating excipients or carriers such ascocoa butter, polyethylene glycol or a suppository wax which are solidat ambient temperature but liquid at body temperature and therefore meltin the rectum or vaginal cavity and release the active compound.

Solid dosage forms for oral administration include capsules, tablets,pills, powders, and granules. In such solid dosage forms, the activecompound is mixed with at least one inert, pharmaceutically acceptableexcipient or carrier such as sodium citrate or dicalcium phosphateand/or a) fillers or extenders such as starches, lactose, sucrose,glucose, mannitol, and silicic acid, b) binders such as, for example,carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidinone,sucrose, and acacia, c) humectants such as glycerol, d) disintegratingagents such as agar-agar, calcium carbonate, potato or tapioca starch,alginic acid, certain silicates, and sodium carbonate, e) solutionretarding agents such as paraffin, f) absorption accelerators such asquaternary ammonium compounds, g) wetting agents such as, for example,cetyl alcohol and glycerol monostearate, h) absorbents such as kaolinand bentonite clay, and i) lubricants such as talc, calcium stearate,magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate,and mixtures thereof. In the case of capsules, tablets and pills, thedosage form may also comprise buffering agents.

Solid compositions of a similar type may also be employed as fillers insoft and hard-filled gelatin capsules using such excipients as lactoseor milk sugar as well as high molecular weight polyethylene glycols andthe like. The solid dosage forms of tablets, dragees, capsules, pills,and granules can be prepared with coatings and shells such as entericcoatings and other coatings well known in the pharmaceutical formulatingart. They may optionally contain opacifying agents and can also be of acomposition that they release the active ingredient(s) only, orpreferentially, in a certain part of the intestinal tract, optionally,in a delayed manner. Examples of embedding compositions that can be usedinclude polymeric substances and waxes. Solid compositions of a similartype may also be employed as fillers in soft and hard-filled gelatincapsules using such excipients as lactose or milk sugar as well as highmolecular weight polethylene glycols and the like.

The active compounds can also be in micro-encapsulated form with one ormore excipients as noted above. The solid dosage forms of tablets,dragees, capsules, pills, and granules can be prepared with coatings andshells such as enteric coatings, release controlling coatings and othercoatings well known in the pharmaceutical formulating art. In such soliddosage forms the active compound may be admixed with at least one inertdiluent such as sucrose, lactose or starch. Such dosage forms may alsocomprise, as is normal practice, additional substances other than inertdiluents, e.g., tableting lubricants and other tableting aids such amagnesium stearate and microcrystalline cellulose. In the case ofcapsules, tablets and pills, the dosage forms may also comprisebuffering agents, They may optionally contain opacifying agents and canalso be of a composition that they release the active ingredient(s)only, or preferentially, in a certain part of the intestinal tract,optionally, in a delayed manner. Examples of embedding compositions thatcan be used include polymeric substances and waxes.

Dosage forms for topical or transdermal administration of a compound ofthis invention include ointments, pastes, creams, lotions, gels,powders, solutions, sprays, inhalants or patches. The active componentis admixed under sterile conditions with a pharmaceutically acceptablecarrier and any needed preservatives or buffers as may be required.Ophthalmic formulation, ear drops, and eye drops are also contemplatedas being within the scope of this invention. Additionally, the presentinvention contemplates the use of transdermal patches, which have theadded advantage of providing controlled delivery of a compound to thebody. Such dosage forms can be made by dissolving or dispensing thecompound in the proper medium. Absorption enhancers can also be used toincrease the flux of the compound across the skin. The rate can becontrolled by either providing a rate controlling membrane or bydispersing the compound in a polymer matrix or gel.

As described generally above, the compounds of the invention are usefulas inhibitors of ERK protein kinases. In one embodiment, the compoundsand compositions of the invention are inhibitors of one or both of ERK1and ERK2 protein kinases and thus, without wishing to be bound by anyparticular theory, the compounds and compositions are particularlyuseful for treating or lessening the severity of a disease, condition,or disorder where activation of one or both of ERK1 and ERK2 proteinkinases is implicated in the disease, condition, or disorder. Whenactivation of ERK1 and/or ERK2 protein kinases is implicated in aparticular disease, condition, or disorder, the disease, condition, ordisorder may also be referred to as “ERK1- or ERK2-mediated disease”,condition, or disease symptom. Accordingly, in another aspect, thepresent invention provides a method for treating or lessening theseverity of a disease, condition, or disorder where activation of one orboth of ERK1 and ERK2 protein kinases is implicated in said disease,condition, or disorder.

The activity of a compound utilized in this invention as an inhibitor ofERK1 and/or ERK2 protein kinases may be assayed in vitro, in vivo or ina cell line. In vitro assays include assays that determine inhibition ofeither the phosphorylation activity or ATPase activity of activated ERK1or ERK2 protein kinases. Alternate in vitro assays quantitate theability of the inhibitor to bind to ERK1 or ERK2 protein kinases.Inhibitor binding may be measured by radiolabelling the inhibitor priorto binding, isolating the inhibitor/ERK1 or inhibitor/ERK2 complex anddetermining the amount of radiolabel bound. Alternatively, inhibitorbinding may be determined by running a competition experiment where newinhibitors are incubated with ERK1 or ERK2 protein kinases bound toknown radioligands.

The term “measurably inhibit”, as used herein means a measurable changein ERK1 or ERK2 protein kinase activity between a sample comprising saidcomposition and a ERK1 or ERK2 protein kinase and an equivalent samplecomprising ERK1 or ERK2 protein kinase in the absence of saidcomposition. Such measurements of protein kinase activity are known toone of ordinary skill in the art and include those methods set forthherein below.

According to another embodiment, the invention relates to a method ofinhibiting ERK1 or ERK2 protein kinase activity in a patient comprisingthe step of administering to said patient a compound of the presentinvention, or a composition comprising said compound.

The term “ERK-mediated condition” or “disease”, as used herein, meansany disease or other deleterious condition in which ERK is known to playa role. The term “ERK-mediated condition” or “disease” also means thosediseases or conditions that are alleviated by treatment with an ERKinhibitor. Such conditions include, without limitation, cancer, stroke,diabetes, hepatomegaly, cardiovascular disease including cardiomegaly,Alzheimer's disease, cystic fibrosis, viral disease, autoimmunediseases, atherosclerosis, restenosis, psoriasis, allergic disordersincluding asthma, inflammation, neurological disorders andhormone-related diseases. The term “cancer” includes, but is not limitedto the following cancers: breast, ovary, cervix, prostate, testis,genitourinary tract, esophagus, larynx, glioblastoma, neuroblastoma,stomach, skin, keratoacanthoma, lung, epidermoid carcinoma, large cellcarcinoma, small cell carcinoma, lung adenocarcinoma, bone, colon,adenoma, pancreas, adenocarcinoma, thyroid, follicular carcinoma,undifferentiated carcinoma, papillary carcinoma, seminoma, melanoma,sarcoma, bladder carcinoma, liver carcinoma and biliary passages, kidneycarcinoma, myeloid disorders, lymphoid disorders, Hodgkin's, hairycells, buccal cavity and pharynx (oral), lip, tongue, mouth, pharynx,small intestine, colon-rectum, large intestine, rectum, brain andcentral nervous system, and leukemia.

Accordingly, another embodiment of the present invention relates totreating or lessening the severity of one or more diseases in which ERKis known to play a role. Specifically, the present invention relates toa method of treating or lessening the severity of a disease or conditionselected from cancer, stroke, diabetes, hepatomegaly, cardiovasculardisease including cardiomegaly, Alzheimer's disease, cystic fibrosis,viral disease, autoimmune diseases, atherosclerosis, restenosis,psoriasis, allergic disorders including asthma, inflammation,neurological disorders and hormone-related diseases, wherein said methodcomprises administering to a patient in need thereof a compositionaccording to the present invention.

According to another embodiment, the present invention relates to amethod of treating a cancer selected from breast, ovary, cervix,prostate, testis, genitourinary tract, esophagus, larynx, glioblastoma,neuroblastoma, stomach, skin, keratoacanthoma, lung, epidermoidcarcinoma, large cell carcinoma, small cell carcinoma, lungadenocarcinoma, bone, colon, adenoma, pancreas, adenocarcinoma, thyroid,follicular carcinoma, undifferentiated carcinoma, papillary carcinoma,seminoma, melanoma, sarcoma, bladder carcinoma, liver carcinoma andbiliary passages, kidney carcinoma, myeloid disorders, lymphoiddisorders, Hodgkin's, hairy cells, buccal cavity and pharynx (oral),lip, tongue, mouth, pharynx, small intestine, colon-rectum, largeintestine, rectum, brain and central nervous system, and leukemia.

Another embodiment relates to a method of treating melanoma, breastcancer, colon cancer, or pancreatic cancer in a patient in need thereof.

It will also be appreciated that the compounds and pharmaceuticallyacceptable compositions of the present invention can be employed incombination therapies, that is, the compounds and pharmaceuticallyacceptable compositions can be administered concurrently with, prior to,or subsequent to, one or more other desired therapeutics or medicalprocedures. The particular combination of therapies (therapeutics orprocedures) to employ in a combination regimen will take into accountcompatibility of the desired therapeutics and/or procedures and thedesired therapeutic effect to be achieved. It will also be appreciatedthat the therapies employed may achieve a desired effect for the samedisorder (for example, an inventive compound may be administeredconcurrently with another agent used to treat the same disorder), orthey may achieve different effects (e.g., control of any adverseeffects). As used herein, additional therapeutic agents that arenormally administered to treat or prevent a particular disease, orcondition, are known as “appropriate for the disease, or condition,being treated”.

For example, chemotherapeutic agents or other anti-proliferative agentsmay be combined with the compounds of this invention to treatproliferative diseases and cancer. Examples of known chemotherapeuticagents include, but are not limited to, For example, other therapies oranticancer agents that may be used in combination with the inventiveanticancer agents of the present invention include surgery, radiotherapy(in but a few examples, gamma.-radiation, neutron beam radiotherapy,electron beam radiotherapy, proton therapy, brachytherapy, and systemicradioactive isotopes, to name a few), endocrine therapy, biologicresponse modifiers (interferons, interleukins, and tumor necrosis factor(TNF) to name a few), hyperthermia and cryotherapy, agents to attenuateany adverse effects (e.g., antiemetics), and other approvedchemotherapeutic drugs, including, but not limited to, alkylating drugs(mechlorethamine, chlorambucil, Cyclophosphamide, Melphalan,Ifosfamide), antimetabolites (Methotrexate), purine antagonists andpyrimidine antagonists (6-Mercaptopurine, 5-Fluorouracil, Cytarabile,Gemcitabine), spindle poisons (Vinblastine, Vincristine, Vinorelbine,Paclitaxel), podophyllotoxins (Etoposide, Irinotecan, Topotecan),antibiotics (Doxorubicin, Bleomycin, Mitomycin), nitrosoureas(Carmustine, Lomustine), inorganic ions (Cisplatin, Carboplatin),enzymes (Asparaginase), and hormones (Tamoxifen, Leuprolide, Flutamide,and Megestrol), Gleevec™, adriamycin, dexamethasone, andcyclophosphamide. For a more comprehensive discussion of updated cancertherapies see, http://www.nci.nih.gov/, a list of the FDA approvedoncology drugs at http://www.fda.gov/cder/cancer/druglistframe.htm, andThe Merck Manual, Seventeenth Ed. 1999, the entire contents of which arehereby incorporated by reference.

Other examples of agents the inhibitors of this invention may also becombined with include, without limitation: treatments for Alzheimer'sDisease such as Aricept® and Excelon®; treatments for Parkinson'sDisease such as L-DOPA/carbidopa, entacapone, ropinrole, pramipexole,bromocriptine, pergolide, trihexephendyl, and amantadine; agents fortreating Multiple Sclerosis (MS) such as beta interferon (e.g., Avonex®and Rebif®), Copaxone®, and mitoxantrone; treatments for asthma such asalbuterol and Singulair®; agents for treating schizophrenia such aszyprexa, risperdal, seroquel, and haloperidol; anti-inflammatory agentssuch as corticosteroids, TNF blockers, IL-1 RA, azathioprine,cyclophosphamide, and sulfasalazine; immunomodulatory andimmunosuppressive agents such as cyclosporin, tacrolimus, rapamycin,mycophenolate mofetil, interferons, corticosteroids, cyclophosphamide,azathioprine, and sulfasalazine; neurotrophic factors such asacetylcholinesterase inhibitors, MAO inhibitors, interferons,anti-convulsants, ion channel blockers, riluzole, and anti-Parkinsonianagents; agents for treating cardiovascular disease such asbeta-blockers, ACE inhibitors, diuretics, nitrates, calcium channelblockers, and statins; agents for treating liver disease such ascorticosteroids, cholestyramine, interferons, and anti-viral agents;agents for treating blood disorders such as corticosteroids,anti-leukemic agents, and growth factors; and agents for treatingimmunodeficiency disorders such as gamma globulin.

The amount of additional therapeutic agent present in the compositionsof this invention will be no more than the amount that would normally beadministered in a composition comprising that therapeutic agent as theonly active agent. Preferably the amount of additional therapeutic agentin the presently disclosed compositions will range from about 50% to100% of the amount normally present in a composition comprising thatagent as the only therapeutically active agent.

In an alternate embodiment, the methods of this invention that utilizecompositions that do not contain an additional therapeutic agent,comprise the additional step of separately administering to said patientan additional therapeutic agent. When these additional therapeuticagents are administered separately they may be administered to thepatient prior to, sequentially with or following administration of thecompositions of this invention.

The compounds of this invention or pharmaceutically acceptablecompositions thereof may also be incorporated into compositions forcoating implantable medical devices, such as prostheses, artificialvalves, vascular grafts, stents and catheters. Accordingly, the presentinvention, in another aspect, includes a composition for coating animplantable device comprising a compound of the present invention asdescribed generally above, and in classes and subclasses herein, and acarrier suitable for coating said implantable device. In still anotheraspect, the present invention includes an implantable device coated witha composition comprising a compound of the present invention asdescribed generally above, and in classes and subclasses herein, and acarrier suitable for coating said implantable device.

Vascular stents, for example, have been used to overcome restenosis(re-narrowing of the vessel wall after injury). However, patients usingstents or other implantable devices risk clot formation or plateletactivation. These unwanted effects may be prevented or mitigated bypre-coating the device with a pharmaceutically acceptable compositioncomprising a kinase inhibitor. Suitable coatings and the generalpreparation of coated implantable devices are described in U.S. Pat.Nos. 6,099,562; 5,886,026; and 5,304,121. The coatings are typicallybiocompatible polymeric materials such as a hydrogel polymer,polymethyldisiloxane, polycaprolactone, polyethylene glycol, polylacticacid, ethylene vinyl acetate, and mixtures thereof. The coatings mayoptionally be further covered by a suitable topcoat of fluorosilicone,polysaccarides, polyethylene glycol, phospholipids or combinationsthereof to impart controlled release characteristics in the composition.

Another aspect of the invention relates to inhibiting ERK1 or ERK2protein kinase activity in a biological sample or a patient, whichmethod comprises administering to the patient, or contacting saidbiological sample with a compound of the present invention or acomposition comprising said compound. The term “biological sample”, asused herein, includes, without limitation, cell cultures or extractsthereof; biopsied material obtained from a mammal or extracts thereof;and blood, saliva, urine, feces, semen, tears, or other body fluids orextracts thereof.

Inhibition of ERK1 or ERK2 protein kinase activity in a biologicalsample is useful for a variety of purposes that are known to one ofskill in the art. Examples of such purposes include, but are not limitedto, blood transfusion, organ-transplantation, biological specimenstorage, and biological assays.

SYNTHETIC EXAMPLES

As used herein, the term “R_(t)” refers to the HPLC retention time, inminutes, associated with the compound. Unless otherwise indicated, theHPLC method utilized to obtain the reported retention time is asfollows:

-   -   Column: Agilent/ZORBAX SB—C18/5 μm/3.0×150 mm/PN 883975-302/SN        USBM001410    -   Gradient: 10-90% MeCN over 8 minutes    -   Flow: 1.0 mL/minute    -   Detection: 214 nm and 254 nm

Unless otherwise indicated, each ¹H NMR was obtained at 500 MHz in CDCl₃and compound numbers correspond to those compound numbers recited inTable 1.

Example 1

Compound 1-9 was prepared as follows:

2,2,2-Trichloro-1-(4-iodo-1H-pyrrol-2-yl)ethanone: To a stirred solutionof 50 g (235 mmol, 1.0 equiv.) of2,2,2-trichloro-1-(1H-pyrrol-2-yl)-ethanone in dry dichloromethane (400mL) under nitrogen, a solution of iodine monochloride (39 g, 240 mmol,1.02 equivalents) in of dichloromethane (200 mL) was added dropwise. Theresulting mixture was stirred at room temperature for 2 hours. Thesolution was washed with 10% potassium carbonate, water, 1.0 M sodiumthiosulfate, saturated sodium chloride, dried over sodium sulfate,filtered, and concentrated under reduced pressure. The solid wasrecrystallized from hexanes/methyl acetate to afford the title compound(68.5 g, 86%) as a colorless solid (86%). MS FIA: 335.8, 337.8 ES-.

4-Iodo-1H-pyrrole-2-carboxylic acid methyl ester: To a stirred solutionof 2,2,2-trichloro-1-(4-iodo-1H-pyrrol-2-yl) ethanone (68 g, 201 mmol,1.0 equivalent) in dry methanol (400 mL) under nitrogen, was added asolution of sodium methoxide in methanol (4.37 M, 54 mL, 235 mmol, 1.2equivalents) over 10 minutes. The resulting mixture was stirred at roomtemperature for 1 hour. The volatiles were removed under reducedpressure and the crude was then partitioned between water andtert-butylmethyl ether. The organic phase was separated, washed twotimes with water, saturated sodium chloride, dried over sodium sulfate,filtered and concentrated under vacuum to afford the title compound (48g, 96%) as a colorless solid, that was used directly without furtherpurification.

4-Iodo-1-(toluene-4-sulfonyl)-1H-pyrrole-2-carboxylic acid methyl ester:4-Iodo-1H-pyrrole-2-carboxylic acid methyl ester (24.6 g, 98 mmol, 1.0equivalent) was dissolved in dichloromethane (150 mL) and triethylamine(30 mL, 215.6 mmol, 2.2 equivalents). 4-(Dimethylamino)pyridine (1.2 g,9.8 mmol, 0.1 equivalent) and p-toluenesulfonylchloride (20.6 g, 107.8mmol, 1.1 equivalents) were added and the reaction mixture was stirredfor 16 hours at room temperature. The reaction was quenched with 1 M HCland the organic layer was washed with aqueous sodium bicarbonate andbrine. After drying over magnesium sulfate, the solvent was removedunder reduced pressure and the residue was crystallized fromtert-butylmethyl ether, yielding the title compound as a pale yellowsolid (30 g, 75%). R_(t)(min) 8.259 minutes.

4-(4,4,5,5-Tetramethyl-[1,3,2]dioxaborolan-2-yl)-1-(toluene-4-sulfonyl)-1H-pyrrole-2-carboxylicacid methyl ester: To a degassed solution of4-iodo-1-(toluene-4-sulfonyl)-1H-pyrrole-2-carboxylic acid methyl ester(20 g, 49.4 mmol, 1.0 equivalent) and bis(pinacolato)diborane (15 g, 65mmol, 1.3 equivalents) in DMF (200 mL) under nitrogen, was addeddichloro[1,1′-bis(diphenylphosphino)ferrocene]palladium (II)dichloromethane adduct (3.6 g, 4.9 mmol, 0.1 equivalent). The reactionmixture was then stirred at 80° C. for 18 hours. After removing the DMFunder reduced pressure, the resulting thick oil residue was suspended indiethyl ether (500 mL) and a solid precipitated immediately. This solidwas removed by filtration and the filtrate was washed with 1M HCl,water, brine and dried over MgSO₄. Concentration afforded the titlecompound as a white solid and used without further purification (10 g,50%). LC/MS: R_(t)(min) 4.6; 406.4 ES+. MS FIA: 406.2 ES+. ¹HNMR δ 1.2(s, 12H), 2.35 (s, 3H), 3.8 (s, 3H), 7.2 (m, 3H), 7.8 (d, 2H), 8.0 (s,1H).

N,N′-2-(5-Chloro-4-iodo-pyridyl)-isopropylamine:

Method A. (Microwave)

In a 10 mL microwave tube, 5-chloro-2-fluoro-4-iodopyridine (1.0 g, 3.9mmol, 1.0 equivalent) was dissolved in DMSO (4.0 mL) and thenispropylamine (0.99 mL, 11.7 mmol, 3.0 equivalents) was added. The tubewas sealed and placed under microwave irradiation for 600 sec at 150° C.

This reaction was repeated six times. The reaction mixtures werecombined, then diluted in ethyl acetate and washed with water. Afterdrying over sodium sulfate, the solvent was evaporated to afford thetitle compound as a thick brown oil (5.6 g, 80%) which was used directlywithout further purification. R_(t)(min) 4.614; MS FIA: 296.9 ES+.¹HNMRsssssss δ 1.25 (d, 6H), 3.65 (m, 1H), 7.15 (s, 1H), 7.75 (s, 1H).

Method B: (Thermal)

5-Chloro-2-fluoro-4-iodopyridine (400 mg, 1.55 mmol, 1.0 equivalent) wasdissolved in ethanol (5.0 mL) and then isopropylamine (0.66 mL, 7.8mmol, 5.0 equivalents) was added. The resulting solution was stirred at80° C. for 48 hours. The reaction mixture was then diluted in ethylacetate and washed with water. After drying over sodium sulfate, thesolvent was evaporated and a thick brown oil was obtained, which wasthen purified by flash chromatography on silica gel eluting withmixtures of hexanes/ethyl acetate (from 99:1 to 80:20) to afford thetitle compound as a pale yellow solid (96 mg, 21%).

4-(5-Chloro-2-isopropylaminopyridin-4-yl)-1-(toluene-4-sulfonyl)-1H-pyrrole-2-carboxylicacid methyl ester: To a solution ofN,N′-2-(5-chloro-4-iodo-pyridyl)-isopropylamine (0.53 g, 1.8 mmol, 1.0equivalent) and4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-1-(toluene-4-sulfonyl)-1H-pyrrole-2-carboxylicacid methyl ester (0.78 g, 1.8 mmol, 1.0 equivalent) in DME (4.0 mL) wasadded a solution of aqueous 2 M sodium carbonate (1.0 mL) followed byPd(PPh₃)₄ (0.21 mg, 0.18 mmol, 0.1 equivalent). The microwave tube wassealed and the reaction mixture was irradiated by microwave for 1800sec. at 170° C. The crude of six reactions were combined and diluted inethyl acetate and washed with water. After drying the organic layer withsodium sulfate, the solvent was removed and the resulting thick oil wasadsorbed on silica gel. The crude was then purified by flashchromatography on silica, eluting with hexanes/ethyl acetate mixtures(from 99:1 to 70:30) to afford the title compound as a yellow solid (3.1g, 61% over two steps). R_(t)(min) 6.556. MS FIA: 448.1 ES+. ¹HNMR δ1.45 (d, 6H), 2.5 (s, 3H), 3.81 (s, 3H), 6.8 (s, 1H), 7.35 (s, 1H), 7.4(d, 2H), 8.0 (m, 3H), 8.3 (s, 1H).

4-(5-Chloro-2-isopropylaminopyridin-4-yl)-1-(2,4,6-trimethylbenzenesulfonyl)-1H-pyrrole-2-carboxylicacid methyl ester: To a solution ofN,N′-2-(5-chloro-4-iodopyridyl)-isopropylamine (96 mg, 0.32 mmol, 1.0equivalent) and4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-1-(2,4,6-trimethylbenzenesulfonyl)-1H-pyrrole-2-carboxylicacid methyl ester (152 mg, 0.35 mmol, 1.1 equivalents) in DME (2 mL),was added a solution of aqueous 2 M sodium carbonate (0.2 mL) followedby Pd(PPh₃)₄ (37 mg, 0.032 mmol, 0.1 equivalent). The reaction mixturewas stirred at 80° C. for 16 hours. The crude was diluted in ethylacetate and washed with water. After drying the organic layer withsodium sulfate, the solvent was removed and the resulting thick oil wasadsorbed on silica gel. The crude was then purified by flashchromatography on silica, eluting with hexanes/ethyl acetate mixtures(from 99:1 to 80:20) to afford the title compound as a yellow solid (65mg, 43%). R_(t)(min) 7.290. MS FIA:476.1 ES+.

4-(5-Chloro-2-isopropylaminopyridin-4-yl)-1H-pyrrole-2-carboxylic acid:

Method A. (Microwave)

A solution of4-(5-chloro-2-isopropylaminopyridin-4-yl)-1-(toluene-4-sulfonyl)-1H-pyrrole-2-carboxylicacid methyl ester (3.1 g, 6.9 mmol, 1.0 equivalent) in THF (2.0 mL) wasadded to a solution of lithium hydroxide monohydrated (710 mg, 17.3mmol, 2.5 equivalents) in water (3.0 mL). The microwave tube was sealedand the reaction mixture was irradiated by microwave for 1200 sec. at150° C. The crude solution was acidified with aqueous 6N HCl. Thesolvent was evaporated off to afford the title compound which was useddirectly without further purification. R_(t)(min): 3.574. FIA MS: 279.9ES+; 278.2 ES−.

Method B: (Thermal)

A solution of4-(5-chloro-2-isopropylaminopyridin-4-yl)-1-(2,4,6-trimethylbenzenesulfonyl)-1H-pyrrole-2-carboxylicacid methyl ester (0.69 g, 1.4 mmol, 1.0 equivalent) in THF (3.0 mL) wasadded to a solution of lithium hydroxide monohydrated (1.19 g, 29 mmol,20.0 equivalents) in water (3.0 mL). The mixture was then refluxed for 8hours. The crude solution was acidified with aqueous 6N HCl untilcloudy, the organic solvent was partially removed and the productprecipitated. The title compound was isolated by filtration and washedwith water and diethyl ether, yielding a white solid (0.38 g, 96%).

4-(5-Chloro-2-isopropylaminopyridin-4-yl)-1H-pyrrole-2-carboxylic acid[1-(3-chlorophenyl)-2-hydroxyethyl]amide: To a suspension of4-(5-chloro-2-isopropylaminopyridin-4-yl)-1H-pyrrole-2-carboxylic acid(1.93 g, 6.9 mmol, 1.0 equivalent) in DMF (5.0 mL) was added EDCI (1.45g, 7.6 mmol, 1.1 equivalents), HOBt (0.94 g, 6.9 mmol, 1.0 equivalent)and (S)-3-chlorophenylglycynol (1.58 g, 7.6 mmol, 1.1 equivalents).Diisopropylethylamine (2.7 mL) was then added and the resulting mixturewas stirred a room temperature overnight. The mixture was then pouredinto water and extracted with ethyl acetate. After drying over sodiumsulfate, the solvent was removed and the crude was adsorbed on silicagel. Purification was effected by flash chromatography on silica,eluting with mixtures of hexanes/acetone (from 80:20 to 60:40) to affordthe title compound as white solid (1.9 g, 64%). R_(t)(min) 4.981 s. FIAMS: 433.1 ES+; 431.2 ES−. ¹HNMR (CD₃OD) δ 1.31 (d, 6H), 3.85 (m, 3H),5.15 (t, 1H), 7.01 (s, 1H), 7.25 (m, 3H), 7.4 (s, 1H), 7.45 (s, 1H), 7.7(s, 1H), 7.95 (s, 1H).

Example 2

Compound 1-9 was also prepared according to following alternate method:

2,5-Dichloro-4-nitropyridine N-oxide: To a suspension of2-chloro-5-chloropyridine (10 g, 0.067 mol) in acetic anhydride (25 mL)was added hydrogen peroxide 30% (25 mL) in small portions. This mixturewas stirred at room temperature for 24 hours and then heated at 60° C.for 30 hours. After removing the excess of acetic acid under reducedpressure, the residue was added in small portions to concentratedsulfuric acid (15 mL). The resulting solution was added to a mixture ofconcentrated sulfuric acid (15 mL) and fuming nitric acid (25 mL) andthen heated at 100° C. for 90 minutes. The reaction mixture was pouredon ice, neutralized with solid ammonium carbonate and finally withaqueous ammonia until a basic pH was obtained and A precipitate formed.The precipitate was collected by filtration to afford the title compoundas a pale yellow solid (3.1 g), R_(t)(min) 3.75. MS FIA shows no peak.¹HNMR (DMSO-d₆) δ 8.78 (s, 1H), 9.15 (s, 1H).

4-Bromo-2-chloro-5-N-isopropylpyridin-2-amine N-oxide: To2,5-dichloro-4-nitropyridine N-oxide (400 mg, 1.9 mmol) was added acetylbromide (2 mL) very slowly. The reaction mixture was then heated at 80°C. for 10 minutes. The solvent was removed under a stream of nitrogenand the crude product was dried under high vacuum. The crude material(165 mg, 0.62 mmol) was dissolved in ethanol (2 mL), iso-propylamine(0.53 mL) added and the resulting mixture was heated at 80° C. for 2hours. The crude solution was then purified by reversed phase HPLC(acetonitrile/water/TFA 1%) to afford the title compound as a paleyellow solid (60 mg, 36.6%). R_(t)(min) 5.275. MS FIA264.8, 266.9 ES+.

4-(5-chloro-2-isopropylaminopyridin-4-yl)-1H-pyrrole-2-carboxylic acid[1-(3-chlorophenyl)-2-hydroxyethyl]amide (1-9):4-Bromo-2-chloro-5-N-isopropylpyridin-2-amine N-oxide (25 mg, 0.094mmol, 1.0 equivalent) and4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-1-(2,4,6-trimethylbenzensulfonyl)-1H-pyrrole-2-carboxylicacid methyl ester (39 mg, 0.094 mmol, 1.0 equivalent) were dissolved inbenzene (5 mL) then aqueous 2M Na₂CO₃ (1 mL) and Pd(PPh₃)₄ (115.6 mg,0.1 mmol, 0.2 equivalent) were added and the resulting suspension washeated at reflux at 80° C. for 16 hours. The reaction mixture wasdiluted in ethyl acetate, washed with water and dried over anhydroussodium sulfate to afford4-(5-chloro-2-isopropylamino-pyridin-4-yl)-1-(2,4,6-trimethyl-benzenesulfonyl)-1H-pyrrole-2-carboxylicacid methyl ester N-oxide (R_(t)(min) 6.859. MS FIA: 492.0 ES+) whichwas then treated with a 2 M solution of PCl₃ in dichloromethane (1 mL)at room temperature. After 10 minutes, the solvent was removed under astream of nitrogen and the crude oil was dissolved in methanol (1 mL)and aqueous 1 M NaOH (1 mL). The resulting mixture was heated at refluxfor 16 hours then the crude solution was acidified using aqueous 1 M HCland the solvent was removed. The resulting4-(5-chloro-2-isopropylamino-pyridin-4-yl)-1H-pyrrole-2-carboxylic acid(R_(t)(min) 3.527. MS FIA: 279.4 ES+; 278.2 Es−) was suspended in DMF (3mL) together with EDCI (36 mg, 0.19 mmol, 2 equivalents), HOBt (26 mg,0.19 mmol, 2 equivalents), (S)-3-chlorophenylglycinol HCl salt (59 mg,0.28 mmol, 3 equivalents) and DIEA (0.12 mL, 0.75 mmol, 8 equivalents).The resulting mixture was stirred at room temperature for 16 hours. Thereaction mixture was diluted in ethyl acetate, washed with water anddried over sodium sulfate. After removing the solvent under reducedpressure, the crude product was purified by reversed phase HPLC(acetonitrile/water/TFA 1%) to afford the title compound as a whitesolid (4.8 mg, 8.1%).

Example 3

Compound 1-3 was prepared as follows:

2-Chloro-5-methyl-4-nitropyridine N-oxide: The title compound wasprepared in a manner substantially similar to that described by Z.Talik, A. Puszko, Roczniki Chemii Ann. Soc. Chim. Polonorum 1976, 50,2209, as follows. To a suspension of 2-chloro-5-methylpyridine (10 g,0.078 mol) in acetic anhydride (25 mL) was added hydrogen peroxide 30%(25 mL) in small portions. This mixture was stirred at room temperaturefor 24 hours and then heated at 60° C. for 30 hours. After removing theexcess acetic acid under reduced pressure, the residue was added insmall portions to concentrated sulfuric acid (15 mL). The resultingsolution was added to a mixture of concentrated sulfuric acid (15 mL)and fuming nitric acid (25 mL) and then heated at 100° C. for 90minutes. The reaction mixture was poured onto ice, neutralized withsolid ammonium carbonate and finally with aqueos ammonia until a basicpH was obtained and a precipitate formed. This precipitate was collectedby filtration to afford the title compound as a pale yellow solid (9.4g, 0.050 mol, R_(t)(min) 3.272, FIA ES+ 188.9, ES− 188.0).

2-((S)-1-Hydroxymethylpropylamino)-5-methyl-4-nitro-pyridine N-oxide:2-Chloro-5-methyl-4-nitropyridine N-oxide (200 mg, 1.06 mmol, 1.0equivalent) was dissolved in ethanol (1.5 mL). (S)-2-Aminobutanol (284mg, 3.2 mmol, 3.0 equivalent) was then added and the resulting mixturewas refluxed for 16 hours. The crude solution was then purified byreversed phase HPLC (acetonitrile/water/TFA) to afford the titlecompound as a brown solid (146 mg, 0.61 mmol, R_(t)(min) 3.787; FIA ES+241.8, ES− not observed).

Acetic acid 2-(4-bromo-5-methylpyrinin-2-ylamino)-butyl ester:2-((S)-1-Hydroxymethylpropylamino)-5-methyl-4-nitro-pyridine N-oxide(146 mg, 0.61 mmol) was dissolved in acetyl bromide (1.5 mL). Themixture was then heated at 90° C. for 3 hours. The acteyl bromide wasevaporated off under a stream of nitrogen and the crude material wasdissolved in a solution of 2M PCl₃ in dichloromethane (2 mL). Theresulting mixture was stirred at room temperature for 1 hour and thereaction mixture poured into an aqueous solution of saturated NaHCO₃ andextracted with ethyl acetate. The organic layer was washed with water,the solvent was then dried over Na₂SO₄ and removed under reducedpressure to afford the title compound as a brown oil (149 mg,(R_(t)(min) 4.146; FIA ES+ 300.9, ES− not observed).

4-[2-(S)-(1-Acetoxymethylpropylamino)-5-methylpyridin-4-yl]-1-(2,4,6-trime-thylbenzensulfonyl)-1H-pyrrole-2-carboxylicacid methyl ester: To a solution of acetic acid2-(4-bromo-5-methylpyrinin-2-ylamino)-butyl ester (149 mg, 0.5 mmol, 1.0equivalent) and4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-1-(2,4,6-trimethylbenzensulfonyl)-1H-pyrrole-2-carboxylicacid methyl ester (215 mg, 0.50 mmol, 1.0 equivalent) in benzene (5 mL)was added aqueous 2M Na₂CO₃ (1 mL) and Pd(PPh₃)₄ (115.6 mg, 0.1 mmol,0.2 equivalent). After heating at reflux for 16 hours, the mixture waspoured in water and extracted with ethyl acetate. The organic extractwas dried over Na₂SO₄ and the solvent removed under reduced pressure toafford the title compound (R_(t)(min) 6.684; FIA ES+ 528.3, ES− notobserved) which was carried into the next step.

4-[2-(S)-Hydroxymethylpropylamino)-5-methylpyridin-4-yl]-1H-pyrrole-2-carboylicacid [1-(S)-(3-chlorophenylgylcinol]amide (1-3): The crude4-[2-(S)-(1-acetoxymethylpropylamino)-5-methylpyridin-4-yl]-1-(2,4,6-trimethylbenzensulfonyl)-1H-pyrrole-2-carboxylicacid methyl ester was dissolved in methanol (1.5 mL) and aquous 1M, NaOH(2 mL) and the mixture heated at reflux for 16 hours. After acidifyingwith aqueous 1M HCl (2.2 mL), the solvent was removed under reducedpressure and the crude was then suspended in DMF (5 mL). After addingEDCI (192 mg, 1.0 mmol), HOBt (135 mg, 1.0 mmol) and DIEA (0.48 mL, 3.0mmol), the mixture was stirred for 30 minutes at room temperature beforeadding. (S)-3-chlorophenylglycinol HCl salt (312 mg, 1.5 mmol) and thereaction mixture was then stirred for 16 hours at room temperature. Thereaction mixture was dissolved in ethyl acetate, washed with water, theorganic layer was dried over Na₂SO₄ and the solvent was removed underreduced pressure. The crude residue was purified by reversed phase HPLC(acetonitrile/water/TFA) to afford the title compound as a colorlesssolid (29.3 mg, 0.07 mmol, R_(t)(min) 4.563; FIA ES+ 443.1, ES− 441.5,ES+ 443.1, ES− 441.5; ¹HNMR (CD₃OD) δ 1.0 (t, 3H), 1.50 (m, 1H), 1.7 (m,1H), 2.3 (s, 3H), 3.5 (m, 1H), 3.7 (m, 2H), 3.8 (m, 2H), 5.1 (t, 1H),7.0 (s, 1H), 7.3 (m, 4H), 7.4 (two s, 2H), 7.6 (s, 1H).

Example 4 Characterization Data

Compounds of the present invention were prepared by methodssubstantially similar to those described in the above Examples 1-3 andby methods known to one of ordinary skill in the art. Thecharacterization data for these compounds is summarized in Table 3 belowand includes HPLC, MS, and ¹H NMR data. Unless specified otherwise, the¹H NMR data was obtained at 500 MHz and all reported chemical shifts areppm. Compound numbers correspond to the compound numbers listed inTables 1, 2, and 3. As used herein, the term “R_(t)” refers to theretention time, in minutes, obtained for the designated compound usingthe HPLC method described above. Where more than one analyticmeasurement was obtained for any given compound, as described herein,only a single exemplary measurement is provided.

TABLE 3 Characterization Data for Selected Compounds of Formula I Cmpd #M + 1 R_(t) ¹H NMR I-1 413.00 2.10 (CD₃OD)1.3(d, 6H), 2.3(s, 3H), 3.7(m,3H), 5.1(2, 1H), 6.9(s, 1H), 7.2(m, 4H), 7.4(bs, 2H), 7.6(s, 1H) I-2379.20 2.00 (CD₃OD)1.3(d, 6H), 2.3(s, 3H), 3.85(m, 3H), 5.15(t, 1H), 6.99s, 1H), 7.2(t, 1H), 7.3(m, 6H), 7.55(s, 1H) I-3 443.10 2.10(CD₃OD)1.0(t, 3H), 1.5(m, 1H), 1.7(m, 1H), 2.3(s, 3H), 3.5(m, 1H),3,7(m, 2H), 3.8(m, 2H), 5.1(t, 1H), 7.0(s, 1H), 7.3(m, 4H), 7.4(two s,2H), 7.6(s, 1H) I-4 393.30 2.10 (CD₃OD)1.0(t, 3H), 1.3(d, 3H), 1.65(m,2H), 2.35(s, 3H), 3.6(m, 1H), 3.8(m, 2H), 5.15(t, 1H), 6.95(s, 1H),7.2(t, 1H), 7.3(2, 3H), 7.4(d, 1H), 7.45(s, 1H), 7.6(s, 1H) I-5 427.202.40 (CD₃OD)1.0(t, 3H), 1.2(d, 3H), 1.6(m, 2H), 2.3(s, 3H), 3.75(m, 1H),3.85(m, 2H), 5.15(t, 1H), 6.95(s, 1H), 7.3(m, 4H), 7.5(two s, 2H),7.6(s, 1H) I-6 427.10 2.30 (CD₃OD)0.9(, 3H), 1.25(d, 3H), 1.55(m, 2H),2.25(s, 3H), 3.7(m, 1H), 3.85(m, 2H), 5.15(t, 1H) I-7 427.10 2.40(CD₃OD)1.1(d, 6H), 1.9(m, 1H), 2.35(s, 3H), 3.15(d, 1H), 3.8(m, 2H),5.2(m, 1H), 7.0(s, 1H), 7.3(m, 4H), 7.4(s, 1H), 7.6(s, 1H) I-8 411.102.20 (CD₃OD)0.65(m, 2H), 0.95(m, 2H), 2.4(s, 3H), 2.65(m, 1H), 3.8(m,2H), 5.15(t, 1H), 7.0(s, 1H), 7.2(t, 1H), 7.3(m, 3H), 7.4(s, 1H),7.45(s, 1H), 7.75(s, 1H) I-9 433.70 2.30 (CD₃OD)1.2(d, 6H), 3.8(m, 2H),3.85(m, 1H), 5.1(t, 1H), 7.0(s, 1H), 7.2(m, 3H), 7.35(s, 1H),7.4(7.65(s, 1H), 7.9(s, 1H) I-10 399.90 2.10 (CD₃OD)1.2(d, 6H), 3.8(d,2H), 3.9(m, 1H), 5.1(t, 1H), 6.6(s, 1H), 7.2(t, 1H), 7.3(m, 5H), 7.45(s,1H), 7.9(s, 1H) I-11 415.10 1.90 (CD₃OD)1.25(d, 3H), 3.5(m, 1H), 3.7(m,1H), 3.8(m, 2H), 3.9(m, 1H), 5.2(t, 1H), 7.2(t, 1H), 7.3(t, 2H), 7.35(m,2H), 7.45(s, 1H), 7.65(s, 1H), 7.9(s, 1H) I-12 449.00 2.20 (CD₃OD)1.2(d,3H), 3.5(m, 1H), 3.7(m, 1H), 7.3(m, 3H), 7.4(s, 1H), 7.45(s, 1H), 7.7(s,1H), 7.9(s, 1H) I-13 462.90 2.20 (CD₃OD)1.0(t, 3H), 1.6(m, 1H), 1.7(m,1H), 3.55(m, 1H), 3.7(m, 2H), 3.8(m, 2H), 5.15(2, 1H), 7.1(s, 1H),7.2(m, 3H), 7.4(s, 1H), 7.5(s, 1H), 7.7(s, 1H), 7.9(s, 1H) I-14 429.002.00 (CD₃OD)1.0(t, 3H), 1.55(m, 1H), 1,75(m, 1H), 3.5(m, 1H), 3.7(m,2H), 3.8(m, 2H), 5.1(t, 1H), 7.1(s, 1H), 7.2(d, 1H), 7.3(t, 2H), 7.35(m,2H), 7.4(s, 1H), 7.7(s, 1H), 7.9(s, 1H) I-15 447.10 2.50 (CD₃OD)1.0(t,2H), 1.3(d, 3H), 1.7(m, 2H), 3.7(m, 1H), 3.85(m, 2H), 5.15(2, 1H),7.1(s, 1H), 7.25(m, 3H). 7.4(s, 1H), 7.5(s, 1H), 7.7(s, 1H) I-16 477.002.40 (CD₃OD)1.0(t, 314), 1.6(m, 1H), 1.8(m, 1H), 3.6(m, 1H), 3.7(m, 2H),3.85(m, 2H), 3.9(s, 3H), 5.1(t, 1H), 7.1(s, 1H), 7.25(m, 1H), 7.3(m,2H), 7.4(2s, 2H), 7.7(s, 1H), 7.95(s, 1H) I-17 433.00 2.30 (CD₃OD):8.0(s, 1H), 7.7(s, 1H), 7.25-7.5(m, 6H), 5.15(m, 1H), 3.8-3.95(m, 3H),1.3(d, 6H) I-18 449.00 2.36 (CD₃OD)7.96(s, 1H); 7.7(s, 1H); 7.48(s, 1H);7.42(s, 1H); 7.32(s, 2H); 7.24(s, 2H); 7.2(s, 1H); 5.15(t, 1H);3.8-4.0(m. 5H); 3.72(m, 1H); 3.57(m, 1H); 1.3(s, 3H)

Example 5 Synthesis of Prodrugs

Prodrugs of formula II are prepared from the hydroxyl compounds offormula I by a variety of methods known to one of ordinary skill in theart. These methods include, but are not limited to, acylation by adesired carboxylic acid or phosphate formation. When the hydroxyl moietyof formula 1 is acylated by a desired amino acid, the amino moiety ofthe amino acid may be optionally protected by a suitable aminoprotecting group as described herein supra.

The preparation of the L-valine prodrug of compound 1-9 is described indetail below.

(2S)-(S)-2-(4-(5-chloro-2-(isopropylamino)pyridine-4-yl)-1H-pyrrole-2-carboxamido)-2-(3-chlorophenyl)ethyl-2-amino-2-methylbutanoate(II-1): To a solution of compound 1-9 (1 g, 2.3 mmol, 1.0 equivalent) indichloromethane (50 mL) were added DIEA (1.1 mL, 6.9 mmol, 3.0equivalent) and N—BOC-L-Valine (1.2 g, 5.52 mmol, 2.4 equivalents).PyBOP (2.9 g, 5.75 mmol, 2.5 equivalents.) was then added slowly and theresulting mixture was stirred at room temperature for 48 hours. Themixture was then washed with water and dried over sodium sulfate. Thecrude solid was adsorbed on silica and then purified by flashchromatography eluting with mixtures of hexane/ethyl acetate (from 90:10to 50:50), yielding the Boc-protected compound as a white solid (786mg). This intermediate (761 mg, 1.2 mmol) was dissolved in dioxane (1mL) and treated with a solution of 4 M HCL in dioxane. The resultingmixture was stirred for 16 hours at room temperature. The solvent wasthen removed and the 2×HCl salt of the title compound was obtained as awhite solid (571 mg). HPLC R_(t): 4.56 minutes. FIA MS: 531.9 ES+; 529.8ES−. LC/MS: R_(t): 2.07 minutes; 532.0 ES+; 530.1 ES−. ¹HNMR (CD₃OD) δ0.9 (dd, 6H), 1.35 (d, 6H), 2.2 (m, 1H), 3.9 (m, 2H), 4.7 (m, 2H), 5.6(m, 1H), 7.1 (s, 1H), 7.3 (d, 1H), 7.35 (t, 1H), 7.4 (d, 1H), 7.5 (s,1H), 7.6 (s, 1H), 7.75 (s, 1H), 7.95 (s, 1H).

The preparation of a phosphate prodrug of compound 1-9 is described indetail below.

di-tert-Butyl4-(5-chloro-2-(isopropylamino)pyridine-4-yl)-N-((S)-1-(3-chlorophenyl)-2-hydroxyethyl)-1H-pyrrole-2-carboxamidephosphate: Compound 1-9 (1 g, 2.3 mmol, 1.0 equivalent) and tetrazole(241 mg, 3.45 mmol, 1.5 equivalents) were dissolved in dichloromethane(5 mL) and acetonitrile (5 mL) under nitrogen at room temperature.Di-tert-butyl diisopropyl phosphoamidite (1.1 mL, 3.45 mmol, 1.5equivalents) was added dropwise and the resulting mixture was stirredfor 16 hours. The reaction mixture was then cooled on an ice bath,treated with a solution of 6 M tert-butylhydroxyperoxide (3 mL) andstirred for 20 minutes. The clear solution was diluted indichloromethane and small amount of methanol, washed with Na₂S₂O₃, waterand dried over sodium sulfate. The crude oil was adsorbed on silica geland was first purified by flash chromatography eluting with mixtures ofhexane/acetone (from 90:10 to 60:40) and then by reversed phase HPLC(acetonitrile/water/1% TFA), yielding the di-t-butyl ether intermediateas a white solid (336 mg). HPLC R_(t): 6.53 minutes, MS FIA: 625.0 ES+;623.1 ES−.

4-(5-Chloro-2-(isopropylamino)pyridine-4-yl)-N-((S)-1-(3-chlorophenyl)-2-hydroxyethyl)-1H-pyrrole-2-carboxamidephosphate (II-2): The t-butyl phosphate intermediate (336 mg, 0.54 mmol)was suspended in dioxane (5 mL) and a solution of 4 M HCL in dioxane wasadded. The resulting mixture was stirred at room temperature for 1 hour.The solvent was then removed and the free phosphate was then dissolvedin a solution of DMSO (15 mL), methanol (50 mL) and water (25 mL) andtreated with a solution of 2 M Na₂CO₃ (0.25 mL). Methanol was removedunder reduced pressure and the aqueous/DMSO mixture was remove using toa liophilizer to afford the title compound as an off white solid (187mg). HPLC R_(t): 4.24 minutes. FIA MS: 512.9 ES+; 510.9 ES−. LC/MS:R_(t) 2.39 minutes; 512.9 ES+; 510.9 ES−. ¹HNMR (CD₃OD) δ 1.2 (d, 6H),3.9 (m, 1H), 4.1 (dm, 2H), 5.1 (m, 1H), 6.7 (s, 1H), 7.2 (d, 1H), 7.25(t, 1H), 7.3 (m, 2H), 7.45 (s, 1H), 7.55 (s, 1H), 7.9 (s, 1H).

Example 6

ERK2 Inhibition Assay

Compounds were assayed for the inhibition of ERK2 by aspectrophotometric coupled-enzyme assay (Fox et al (1998) Protein Sci 7,2249). In this assay, a fixed concentration of activated ERK2 (10 nM)was incubated with various concentrations of the compound in DMSO (2.5%)for 10 minutes at 30° C. in 0.1 M HEPES buffer, pH 7.5, containing 10 mMMgCl₂, 2.5 mM phosphoenolpyruvate, 200 μM NADH, 150 μg/mL pyruvatekinase, 50 μg/mL lactate dehydrogenase, and 200 μM erktide peptide. Thereaction was initiated by the addition of 65 μM ATP. The rate ofdecrease of absorbance at 340 nM was monitored. The IC₅₀ was evaluatedfrom the rate data as a function of inhibitor concentration.

Compounds of the present invention we found to be inhibitors of ERK2protein kinase. In certain embodiments, compounds were found to inhibitERK2 kinase at <0.1 μM. In other embodiments, compounds were found toinhibit ERK2 kinase at <0.01 μM.

Example 7

ERK1 Inhibition Assay

Compounds are assayed for the inhibition of ERK1 by a spectrophotometriccoupled-enzyme assay (Fox et al (1998) Protein Sci 7, 2249). In thisassay, a fixed concentration of activated ERK1 (20 nM) is incubated withvarious concentrations of the compound in DMSO (2.0%) for 10 minutes at30° C. in 0.1 M HEPES buffer, pH 7.6, containing 10 mM MgCl₂, 2.5 mMphosphoenolpyruvate, 200 μM NADH, 30 μg/mL pyruvate kinase, 10 μg/mLlactate dehydrogenase, and 150 μM erktide peptide. The reaction isinitiated by the addition of 140 μM ATP (20 μL). The rate of decrease ofabsorbance at 340 nM is monitored. The K_(i) is evaluated from the ratedata as a function of inhibitor concentration.

While we have described a number of embodiments of this invention, it isapparent that our basic examples may be altered to provide otherembodiments that utilize the compounds and methods of this invention.Therefore, it will be appreciated that the scope of this invention is tobe defined by the appended claims rather than by the specificembodiments that have been represented by way of example.

We claim:
 1. A compound of formula I:

or a pharmaceutically acceptable salt thereof, wherein: R¹ is a C₁₋₆aliphatic group, wherein R¹ is optionally substituted with up to 2groups independently selected from —OR or —C₁₋₃ haloalkyl; each R isindependently hydrogen or C₁₋₄ aliphatic; R² is R, fluoro, or chloro; mis 0, 1, or 2; and R³ is hydrogen, C₁₋₃ aliphatic, fluoro, or chloro;wherein each aliphatic group is, independently, a saturated orunsaturated straight or branched hydrocarbon chain or monocyclicnon-aromatic hydrocarbon.
 2. The compound according to claim 1, whereinR¹ is C₁₋₄ aliphatic optionally substituted with —OR or —C₁₋₃ haloalkyl.3. The compound according to claim 2, wherein R¹ is C₁₋₄ aliphaticoptionally substituted with —OH, —CHF₂, —CH₂F, or —CF₃.
 4. The compoundaccording to claim 3, wherein R¹ is isopropyl, 2-butyl, cyclopropyl, orethyl, wherein each moiety is optionally substituted with —OH or —CF₃.5. The compound according to claim 1, wherein R² is hydrogen, C₁₋₃aliphatic, or chloro.
 6. The compound according to claim 1, wherein R³is hydrogen, methyl, or chloro.
 7. A compound selected from the groupconsisting of:


8. A composition comprising a compound according to claim 1 and apharmaceutically acceptable carrier, adjuvant, or vehicle.
 9. Thecompound according to claim 1, wherein: R¹ is isopropyl or 2-butyl,wherein R¹ is optionally substituted with one —OH; R² is H or Cl; m is1; and R³ is Cl or methyl.
 10. The compound


11. A composition comprising a compound according to claim 10 and apharmaceutically acceptable carrier, adjuvant, or vehicle.
 12. Apharmaceutically acceptable salt of the Compound


13. A composition comprising a pharmaceutically acceptable salt ofcompound 1-9 according to claim 12 and a pharmaceutically acceptablecarrier, adjuvant, or vehicle.